© National Instruments | 4-9RMX Programmable Power Supplies User Manual• External monitoring of the output voltage (V MON)—You can monitor the outputvoltage of each unit from pin 25 of the J1 connector. To calculate the total output voltage,add the monitor values of the master unit and the slave unit.• External monitoring of the output current (I MON)—This can only be monitored frompin 25 on the master unit's J1 connector.• Status Monitors—You can monitor the status of the following items from the J2 connectoron the master unit and from the slave unit: constant-voltage mode (CV STATUS),constant-current mode (CC STATUS), output on, POWER switch on, and alarms.Remote SensingTo perform remote sensing, connect the RMX programmable power supplies in series, and thenconnect the sensing cables to them as shown in the following figure.Caution If the sensing cables are not connected properly, the load may be exposedto excessive voltage, and the RMX programmable power supplies may be damaged.When the load cables are distributed over longer distance, the phase shifting due towiring inductance and capacitance may go beyond the limit and result in oscillation.To prevent such oscillation, connect an electrolytic capacitor with several hundredsto several tens of thousands μF across the load.Use an electrolytic capacitor with a withstand voltage that is 120% or more of thetotal of the rated output voltages of the RMX programmable power supplies that areconnected in series.Figure 4-5. Connecting the Sensing Cables During Series Operation+ +– –CConnect anelectrolyticcapacitor acrossthe load asnecessary.Load+S-S+S-SOutput terminalChassis terminalSensing terminalUnit 1Unit 2Output terminalChassis terminalSensing terminal
