6622a manual

6622a manual

During the warranty period Agilent Technologies will, at its option, either repair or replace products which prove to be defective. Agilent does not warrant that the operation for the software, firmware, or hardware shall be uninterrupted or error free. Return the instrument to an Agilent Technologies Sales and Service Office for service and repair to ensure that safety features are maintained. The yellow change sheet may also the serial number is a different sequential number assigned contain information for correcting errors in the manual.Each output board is actually an output channel that can be individually selected and controlled over the GPIB or from The following paragraphs provide block diagram level the supply's front panel. Each output board those on the schematic so that the diagrams can be employs series regulation techniques. The regulator element correlated. The contents of each address appear The system micro-computer decodes and executes all sequentially on the data bus (other side of the break).In instructions, and controls all data transfers. It consists of a addition, for all signature analysis tests, jumper W201 must microprocessor, an address decoder, RAM and ROM be moved from the NORM RUN position to the SIG. Logic 0's will always appear on data bus lines D4-D6 when The annunciators provide operating and status information. The STATUS RESET input line from the the V READBACK signal and isolates the multiplexes circuit microcomputer resets the flip-flops.The bleed circuit is activated via the power-on settings that existed before the OV occurred. The bleed circuit maintains stability with large output capacitors under light Down Programmer - Separate transistors in the power loading conditions and helps to keep the output impedance module are used to sink output current and are capable of. This will cause the power module's reference voltage.http://www.gif-king.com/userfiles/blue-parrot-xt250-manual.xml

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Based on this summing action, error series regulators to conduct more and thus increase the amplifier U350 generates the - CL control signal which is output voltage. As the overvoltage comparator signal (OV COMP) will activate shown in Figure 2-9, OV TRIP is the output of a wired OR OV DRIVE and fire the SCR provided that the POV signal can gate and can be activated by either the SENSE. These procedures include a power-on self test. This section contains test procedures that check the b. Perform the performance tests listed below on each operation of the power supply. If the output channel receives a command to go to 0 amps (or any positive current below the minimum programmable value), it will set itself to the minimum programmable value. 3-13 CV Load Effect. If the output channel receives a command to go to 0 amps (or any positive current below minimum programmable current), will itself programmable current. 3-15 CV Noise (PARD). Periodic and random deviations c. This test measures the maintaining the trigger on Channel A as in step f. Note time required for the output voltage to rise to 63% of the that the diode clamp, used in the test setup of Figure 3- High Range Full Scale Voltage (time constant). The following tests check the operation and accuracy of the fixed OV, programmable OV, and the external OV protection circuits. Taking the OV all outputs.It also checks monitoring resistor by 10 to convert to amps and record that the negative current limit has two different values this value (Io). Note also the current reading on the depending upon the output voltage. This test measures the change in output current that results when the ac line voltage changes from the minimum to the maximum value within the specifications. The difference j. Wait 30 minutes and again record the output current.Readback TC b. The following precautions should be observed when handling static-sensitive devices.http://behold.lv/allfiles/blue-point-at123-manual.xml

Most of the maintenance procedures given in this section are performed with power applied and a. Always turn power off before removing or installing protective covers removed. Then use a d. Remove the two screws on each side of front panel.Surface-mount GPIB assemblies are not repairable to the component level. If defective, the entire GPIB assembly must be replaced. BOARD ISOLATION PROCEDURES 4-15 Power-On Self Test The power-on self test sequence performs tests on the GPIB Initial troubleshooting procedures for the power supply are board as well as on each output board in the supply. LOCKED) is generated if an attempt This error is cleared when read. However, if an output is made to turn on the calibration board fails the output board RAM or ROM tests which are mode (see Appendix A, in the. Consequently, analysis tests given in Tables 4-6 through 4-13. Note that after the MODEL command is sent, you must recalibrate jumper pack W202 can be installed in either of two positions each output. Test Setup: Use the test setup described in paragraph 4-23. Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below. Test Setup: Use the test setup described in paragraph 4-23. Connect jumper pack W202 in the normal operating position and set up the signature analyzer as shown below. Signature Analyzer Edge P201 PIN. Then, the self exercise routine begins. This routine runs independently of Overall troubleshooting procedures for an output board are the GPIB board which is ignored by an output board given in Figure 4-9. The response to the VMUX.The signal processor's circuits are shown on the functional analog multiplexer inputs one at a time. The readings and schematic of Figure 6-3, sheet 1, and on the block diagram of associated input nos. For example, if the value of the - 7 V supply is actually - 7.1 V (0.1 V lower than - 7 V), then the LOW value given for pin 25 would read Tables 5-5 through 5-7 list all of the electrical and sales office.

Refer to the list of sales offices at the back of the mechanical components for the power supply. Agilent Part Description Mfg. Code Mfg. Part No. GPIB Board Assembly (See Table 5-6) GPIB Board 06624-60029 Output Board 1 (See Table 5-7) 28480 80W Low Voltage (80WLV) Bd 6621 06621-60023 28480. Agilent Part Description Mfg. Code Mfg. Part No. Chassis Cabling 8120-1348 LINE CORD ASSY 28480 5060-3272 XFMR TO AC SWITCH 28480 5060-3110 FAN WIRE ASSY 28480 5060-3264 XFMR ASSY (PRIMARY) 28480 5060-3271 XFMR - GPIB BIAS. Agilent Part Description Mfg. Mfg. Code Part No. Chassis Mechanical 0515-0890 SCR-MACH M3X0.5 REF CHAS TOP 0515-0923 SCR-MACH M4X0.7 REF XFMR 0515-0906 SCR-MACH M4X0.7 REF H.SINK 0515-0910 SCR-MACH M4X0.7 REF MOD-HS 0515-0920 SCR-MACH M3X0.5 REF FAN-CHAS 0515-0923. Agilent Part Description Mfg. Mfg. Code Part No. C201-205 0160-4835 FXD CER 0.1uf 10% 50VDC 28480 C206 0180-0374 FXD ELECT 10uf 10% 20VDC TAN 56289 150D106X9020B2 C207-212 0160-4835 FXD CER 0-luf 10% 50VDC 28480 C213 0160-4834. Agilent Part Description Mfg. Mfg. Code Part No. SN74LS244N 01295 IC LINE DRIVER TTL LS OCTAL 1820-2024 U212 01295 SN74LS374PC 1820-1997 IC FF TTL LS D-TYPE U213 SN74LS244N 01295 IC LINE DRIVER TTL LS OCTAL 1820-2024 U214 01295. Agilent Part Description Mfg. Mfg. Code Part No. 28480 C300 0160-4833 FXD CER 0.022uF 10% 100V C301 0180-4141 0180-4141 C302 C303-304 0l60-4835 FXD CER 0.1uF 10% 50V 28480 C305 0180-0291 FXD ELECT 1uF 10% 35VDC TAN 56289 150D105X9035A2 C306. Agilent Part Description Mfg. Mfg. Code Part No. C360 40WLV,40WHV 0160-4833 FXD CER 0.022uF 10% 100V 28480 80WLV 0160-4835 FXD CER 0.1uF 10% 50V 28480 80WHV 0160-4834 FXD CER 0.047uF 10% 100VDC 28480 C361 40WLV 0180-4037. Agilent Part Description Mfg. Mfg. Code Part No. C380 40WLV,40WHV NOT USED 80WLV 0180-4037 80WHV 0180-4139 C381 0180-0230 FXD ELECT 1uF 50V 10% TAN 56289 150D105X0050A2 C382 40WLV,40WHV NOT USED 80WLV,80WHV 0160-4831 FXD CER 4700uF 10% 100VDC 28480 C383,384 0160-4791.

Agilent Part Description Mfg. Mfg. Code Part No. C419 0180-0291 FXD ELECT 1uF 10% 35VDC TAN 56289 150D105X9035A2 C420 0160-4048 FXD METPA 0.022uF 20% 250VDC 28480 C421 0160-4832 FXD CER 0.01uF 10% 100VDC 28480 C422 0160-3969. Agilent Part Description Mfg. Mfg. Code Part No. CR342 1901-0033 DIO-SW 13141 1N645 CR343,344 NOT USED CR345-349 1901-0050 DIO-SW 13141 1N4150 CR350 1901-0033 DIO-SW 13141 1N645 CR351 1901-0050 DIO-SW 13141 1N4150 CR352,353 1901-0033 DIO-SW 13141 1N645. Agilent Part Description Mfg. Mfg. Code Part No. L306,307 40WLV, 40WHV NOT USED 80WLV,80WHV 9170-0894 FERRITE BEAD 28480 P301 1251-4246 CONN-POST-TP-HDR 28480 1252-2493 P302 CONN-POST-TYPE-HDR 4 CONT. 28480 P303 40WLV,80WLV 1251-6832 CONN-POST-TP 28480 40WHV,80WHV 1252-1670 CONN-POST-TP. Agilent Part Description Mfg. Mfg. Code Part No. R367 40WLV 8159-0005 FXD FILM ZERO OHMS 28480 40WHV,80WLV, 80WHV NOT USED R368 40WLV,80WLV, NOT USED 80WHV 8159-0005 FXD FILM ZERO OHMS 28480 40WHV NOT USED R369 R370 40WLV,40WHV. Agilent Part Description Mfg. Mfg. Code Part No. R385 FXD FILM 135 5% 5W PW 40WLV 0811-0098 28480 40WHV 0811-1217 FXD FILM 150 5% 5W PW 28480 FXD FILM 75 5% 5W PW 80WLV 0811-0941 28480. Differences between the types are indicated on the schematic. FUNCTIONAL SCHEMATIC DIAGRAMS Sheet 1 - Secondary interface circuits. Before connecting the supply to the power source, check that the position of the line voltage selector card matches the nominal line voltage source (100, 120, 220, or 240 Vac). See Section II in the Operating Manual (Agilent Part No. 5957-6377) for details. ON selects models This surface-mount GPIB assembly applies to models 6621A, 6622A, 6623A, 6624A, and 6627A. OFF starting with the following serial numbers and up: selects models 6625A, 6626A, 6628A, and 6629A. 6621A 3737A03086-up. Notable exceptions to this rule are the horizontal lines flow. Note that in the example shown in Figure A-4 there is beneath control blocks and between sections of shift registers and counters.

Figure A-10 shows indicates which outputs are affected by it. Acts as a miscellaneous terms and symbols that are used in connect switch when active, and a disconnect switch conjunction with the logic symbols, function tables, and when inactive. We have 3 Agilent Technologies 6622A manuals available for free PDF download: Service Manual, Operating Manual, Operating Instructions Manual. Microfiche Part No. Page 2 CERTIFICATION Hewlett-Packard Company certifies that this product met its published specifications at time of shipment from the factory. Hewlett-Packard further certifies that its calibration measurements are traceable to the United States National Bureau of Standards, to the extent allowed by the Bureau's calibration facility, and to the calibration facilities of other International Standards Organization members. Page 3 SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation, service, and repair of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and intended use of the instrument. Hewlett-Packard Company assumes no liability for the customer's failure to comply with these requirements.It is designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters. Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range. It contains information relating to the installation, operation, and programming of these supplies as outlined below. Maintenance and troubleshooting instructions are given in a separate Service Manual (HP Part No. 59576379). Chapter 1. Page 7 Table Of Contents 1 General Information Introduction. 11 Safety Considerations.. 11 Instrument and Manual Identification.. 11 Options. Page 8 Table Of Contents (continued) Positive and Negative Voltages.. 49 Remote Voltage Sensing.. 49 Remote Sense Connections..

50 Output Noise Considerations. Page 10 Page 11 1 General Information Introduction This chapter contains a general description of your power supply, as well as its performance specifications. Information about options, accessories, and HP-IB cables is also provided. This manual describes all five models in the HP 6621A6624A, and 6627A power supply family. Unless stated otherwise, the information in this manual applies to all of these models. Information that is specific to one model only is identified as such in this manual. Page 12 Accessories 10833A HP-IB cable, 1 m (3.3 ft) 10833B HP-IB cable, 2 m (6.6 ft) 10833C HP-IB cable, 4 m (13.2 ft) 10833D HP-IB cable, 0.5 m (1.6 ft) 10834A HP-IB connector extender Slide mount kit (1494-0059) Description The HP 6621A-6624A, and 6627A Multiple Output Linear Power Supplies feature a combination of programming capabilities and linear power supply performance that make systems applications. Page 13 Storage and recall of programmed voltage and current values for all outputs. Queries of programmed functions or settings. Output enable or disable. Programming syntax error detection. Programmable delay time for service request and OCP mask. Voltage, current, and overvoltage calibration. HP-IB interface selftest. Message display capability on the front panel. Output connections are made to rear panel screw terminals. Page 14 The HP-IB board also processes measurement and status data received from the output boards. The power supply has no potentiometers. Each output is individually calibrated over the HP-IB using calibration commands (see Appendix A). Correction factors are calculated by the power supply during calibration and are stored in a non-volatile memory which is located on the supply's HP-IB board. The supply contains no batteries. Page 15 Specifications Table 1-2 lists the performance specifications for the HP 662xA power supplies. Performance specifications describe the instrument's warranted performance.

The service manual, Option 9l0, contains procedures for verifying the performance specifications. Table 1-3 lists the supplemental characteristics for the HP 662xA supplies. Supplemental characteristics are type-tested or typical values, which are based on a product sample and, while representative, are not guaranteed. Page 16 Programming resolution: Average programming step size. Current Sinking ( - Current): Each output can sink as well as source current. The sinking capability is not programmable and depends upon the output voltage. Page 20 Table 1-3. Supplemental Characteristics (continued) Output Impedance: Approximated by a resistance in parallel with an inductance (see graphs in Figure 1-7). Page 21 Figure 1-4. Page 22 Figure 1-5. Page 23 Figure 1-6. Page 24 Figure 1-7. Page 25 2 Installation Introduction This chapter contains instructions for checking and mounting your power supply, connecting your supply to ac power, converting it from one line voltage to another, and connecting the HP-IB cable. The power supply generates operating magnetic fields which may affect the operation of other instruments. If your instrument is susceptible to magnetic fields, do not locate it in the immediate vicinity of the power supply. Page 26 Figure 2-1. Outline Diagram Input Power Requirements You can operate this power supply from a nominal 100 V, 120 V, 220 V or 240 V single phase power source at 47 to 66 Hz. The input voltage range, maximum input current, high line inrush current (PK), and the fuse required for each of the nominal inputs are listed in Table 2-1. You can check the line voltage setting of your supply by examining the door on the line module. Figure 2-4 shows the standard configuration of plugs used by Hewlett-Packard. Below each drawing is the HP part number for the replacement power cord equipped with a plug of that configuration. If a different power cord is required, contact the nearest Hewlett-Packard Sales and Service office.

Page 29 FIRE HAZARD Make sure the replacement fuse is one of the same type (size) and rating (amps) that is consistent with the voltage level you are operating at. Do not use a substitute fuse; use a fuse with the same HP Part number listed in Table 2-2. 6. Close the door of the line module and insert the power cord in the ac input socket. Your power supply is now configured to operate at the voltage you selected. Page 30 Page 31 3 Getting Started Introduction This chapter is intended for the first time user of the supply. Some of the controls and indicators will be used in the Turn On and Checkout procedures that follow. If you have any questions concerning installation or power requirements, review Chapter 2. To turn on your supply, press the front panel LINE switch. When the power is initially applied, the supply performs a series of self tests which last about 3 seconds. This key allows the channels to be selected in forward (c ) or reverse (e) sequence. 36, 37, 83, 83 VSET - Displays the selected output's present voltage setting. The setting can be changed using the numeric entry keys. Page 37, 83, 84 0 to 9 - Set the value of the specified function and (e.g. VSET 16.550) 83 Page 36 Figure 3-4. Typical Display at Power-On Self-Test Errors If the supply fails the power-on self-test, all power supply outputs will remain disabled (off) and the display will indicate the type of failure and the output channel on which it occurred. Figure 3-5 shows that self-test detected an error in output channel 3. Error messages that could appear on the display if self-test fails are listed below. Page 37 Voltage Test 1. Set the voltage of the selected output to 10 V by pressing: VSET 1 0 ENTER 2. Check that the display reads approximately 10 V and 0 A and the CV annunciator is on indicating that the supply is in the constant voltage mode of operation. Overvoltage Test 1. Program the overvoltage protection (OVP) to 19 V by pressing: OV SET 1 9 ENTER 6 ENTER 2.

Set the voltage to 16 V by pressing: VSET 1 3. Check that the display reads approximately 16 V and 0 A. 4. Page 38 6. Check that the display reads approximately 0 volts and the minimum current limit value (0.05 to 0.13A depending upon the model and output, see Table 5-4). Also, check that the front panel CC annunciator is on indicating that the output is in the constant current mode of operation. 7. Set the current to 0.5 A by pressing: ISET. 5 ENTER 8. Check that the display reads approximately 0 V and 0.5 A. 9. Enable the overcurrent protection circuit by pressing: OCP 10. Page 39 OUTPUT The HP BASIC language statement that addresses the power supply to talk and reads back data from the power supply is: ENTER The supply's front panel ADDR annunciator is on when the supply is addressed to talk or to listen. Reading the HP-IB Address Before you can operate your power supply remotely, you need to know its HP-IB address. The address was displayed during the power on sequence described in Normal Self Test Indications, page 35. Page 40 Getting Data From The Supply The supply is capable of measuring the values of its output parameters in response to queries. In this example, the query asks the supply to measure the output voltage at output 1. When you send a query from remote, the supply does not display the response as it did when you executed the command from the front panel. Instead, it holds the response in an output buffer. You can instruct the supply to measure the actual output voltage and current at a specified output using the VOUT.Page 42 Overcurrent Protection. The output will go to the off state (0 volts and min. Page 43 4 Output Connections and Operating Information Introduction This chapter explains how to make connections to the output terminals located on-the rear of your power supply. Some general operating information is included in this chapter to help you understand how the power supply operates under various load conditions.

This information applies whether you are operating the supply via the front panel or the HP-IB. Page 44 Operating Quadrants Figure 4-2 shows the operating locus of your power supply in three quadrants. The area in quadrant 1 shows the operating locus defined by the voltage and current settings of each output. The characteristics shown for quadrant 1 incorporate remote sensing and include the maximum available sense voltage plus load lead drop. The area in quadrant 2 indicates the locus where each output can operate as a current sink. You cannot program current limit values in quadrant 2. Page 45 Figure 4-2. Page 46 A fixed overvoltage threshold of approximately 120% of the maximum rated output voltage is built into each output. Because the fixed overvoltage circuit is biased from the output terminals, it can be activated and provide protection even when the supply is not connected to the ac power line. The OVRST command restores the programmed voltage and current values and clears the OV once the cause of the overvoltage has been eliminated. Page 47 Figure 4-3 Typical Downprogramming Characteristic Below 2.0 V Wire Size Selection FIRE HAZARD Select a wire size large enough to carry short-circuit current without overheating. Two factors must be considered when selecting wire size for load connections: conductor temperature and voltage drop. To satisfy safety requirements, load wires must be heavy enough not to overheat while carrying the short-circuit output current of the unit. Page 48 available in the load leads for prolonged operation into a 5 A load during ac low line at high ambient temperature conditions. There is a similar stipulation for 80 W low voltage outputs at l0 A under the same conditions as above. See Figure 4-2A for worst case voltages available at the output terminals. Table 4-1.

Page 49 Multiple Loads If you are using the as-shipped terminal block strapping pattern (local sensing) and are connecting multiple loads to one output, connect each load to the output terminals using separate connecting wires (see Figure 4-4). This minimizes mutual coupling effects and takes full advantage of the power supply's low output impedance. Each pair of wires should be as short as possible and twisted or bundled to reduce lead inductance and noise pickup. Page 50 sensing is especially useful for CV operation with load impedances that vary or have significant lead resistance. It has no effect during CC operation. Because sensing is independent of other power supply functions, remote sensing can be used regardless of how the power supply is programmed. Page 52 Overvoltage Trigger Connections Each output of your power supply has two OV terminals on its rear panel terminal block. By connecting the OV terminals all in parallel as shown in Figure 4-7, an overvoltage shutdown on any one output will also trigger the overvoltage on the remaining outputs. Any number of OV terminals up to eight sets can be strapped together. Observe polarity when connecting the OV terminals in parallel. Figure 4-7. Page 53 Figure 4-8. External Trigger Circuit The internal equivalent OV circuit is shown in Figure 4-9. Note the internal DC blocking capacitor, bleed resistor and noise bypass capacitors. Remember that each output has an overvoltage protection circuit that fires a crowbar to disable the output for any of the OVERVOLTAGE conditions described in Protection Features, page 44. Page 55 - V terminals of output 1 keeps the total length of the load leads to a minimum and reduces the number of wire connections that must be made at the load itself. CV Operation For CV operation, one output must operate in CC mode and the other output must operate in CV mode.

Page 56 CC Operation For CC operation, set the output voltages as outlined in CV operation (page 55), or alternatively, program the voltage settings of both outputs to the same voltage limit point. Then program the current of each output so that the sum of both currents equals the total desired operating current. The simplest way to accomplish this is to program each output to one half of the total desired operating current. Both outputs will operate in the CC mode. Page 57 Series Operation SHOCK HAZARD Floating voltages must not exceed 240 Vdc. No output terminal may be more than 240 Vdc from chassis ground. Connect in series only outputs that have equivalent current ratings. Each output has a reverse voltage protection diode across its output terminals. The current conducted by this diode is not internally limited by the output. Page 58 CC Operation For CC operation, the current setting of each output must be programmed to the desired operating current. The sum of the voltage settings determines the voltage limit point. As an example, one way to program the voltage of the output is to set the voltage of each output to one half of the total voltage limit point. Page 59 Current All series specifications referring to current are the same as for a single output except for CC load effect, CC load cross regulation, CC source effect, and CC short term drift which are twice the current programming accuracy (including the percentage portion). Load Transient Recovery Time Load transient recovery time is the same to within approximately twice the voltage setting band since the output impedances of the series combination add together. Page 60 Page 61 5 Remote Operation Introduction Chapter 3 introduced you to the basics of remote operation and provided a few simple examples using a Series 200 computer as the HP-IB controller.

This chapter contains all the information required to control your power supply remotely and discusses in greater detail how each of the commands can be implemented. The material covered is intended for any controller capable of using the HP-IB interface functions mentioned in Interface Function, on this page. Page 62 providing the controller is configured to service interrupts. A service request can be generated whenever there is a fault on one of the outputs (up to 4 outputs), a programming error has occurred, or at power on providing certain commands are sent. Service request commands are discussed in detail on page 76. The SRQ annunciator on the front panel display is turned on when the power supply is requesting service from the computer and remains on until the controller conducts a serial poll. Page 63 Power-On Service Request (PON) The power supply can request service from the controller when the power is turned on. This request can be enabled or disabled by sending a PON command (see page 77). When the request is enabled, the supply can generate an SRQ at power-on or when there is a momentary loss in power. You can execute a serial poll to clear the service request. Table 5-7 details the conditions under which a PON command will generate an SRQ. Page 64 The power supply will also return numeric data (ASCII characters) to your computer. The format of the numbers returned depends upon the type of data requested. Table 5-2 gives the format for data returned to the computer in response to any of the queries that are listed. Figure 5-2 (Sheet 1 of 2). Page 65 Figure 5-2 (Sheet 2 of 2). Page 68 Order of Execution When you send a set of instructions to the power supply, they are executed in the order in which they are received. The power supply completes the execution of the present command before executing another command. To send more than one command within the power supply command string, use a semicolon to separate the commands.

This maximizes the rate at which the power supply accepts commands. Terminators Terminators mark the end of a command string. Page 69 Voltage Programming To program voltage, send the output channel and the programmed value. In the example below, output 1 is programmed to 5 V. VSET 1,5 The values you send must always be volts. For example if you want to program 450 millivolts, convert to volts and then send the command: VSET 1. Example 3: VSET 1,5; ISET 1,3 Output 1 is now in the low range programmed to 5 V and 3A. Example 4: VSET 1,10 Now output 1 is in the high range and the current is automatically scaled back from 3 A to the lower current limit of 2.06 A. The output is operating in the same range as that of Example 2. Example 5: VSET 1,20; ISET 1,3 The ISET command will cause the voltage to be scaled back to the low range limit of 7. Page 72 To enable an output after it went into overvoltage, you must first remove the overvoltage condition and then send the OV reset command. To reset output 1 send: OVRST 1 If you send the reset command without first removing the OV condition, the supply will fire the OV again. NOTE If the programmable OV fails, the supply has a fixed OV circuit which will fire the SCR crowbar if the voltage exceeds 120% of the maximum rated output. Page 73 At power-on, each of the registers contain 0 volts and the minimum current limit. To store voltage and current settings, you must specify the register (1 to 10). For example to store the present settings of current and voltage of all your supply's outputs in register 2, send the following command: STO 2 This command will take the programmed voltage and current settings of all output channels and store them in register 2. Page 74 Figure 5-3. Functional Relationship of Status Registers The supply has one serial poll register which services all outputs and provides the user with other power supply statusrelated information as discussed on page 75. Status Register.