UT340 instruments can be powered On and Off remotely by sending the SP1 and SP0 commands via the RS232 remote control interface. The effect is equivalent to pressing the Power button on the front keypad of the UT340.

This feature is not supported on UT320 instruments.

Send SP1 to turn on the UT340 (specifically the low voltage power supply)

Send SP0 to turn off the UT340

Note that the SP command is distinct from the Pulser ON command, PON, which controls active pulsing, but does not affect the power supply of the instrument. The PON command is supported on UT320 and on UT340 instruments.

Send PON1 to enable pulser output and start pulsing.

Send PON0 to stop pulsing the instrument

Error condition cause by AC Power Loss:

If the SP0 command has been sent, and then AC power is interrupted, an error can occur which will prevent the UT340 from being turned back on with the SP1 command.

This error can occur because the ON/OFF state of the instrument's low voltage power supply is recorded in non-volatile memory. If the AC power to the instrument is lost, or if the UT340 is turned off from the rear-panel AC Input switch after SP0 has been sent, then the OFF state of the low voltage supply is retained as the default

When AC power is restored, the controller checks the previous state of the low voltage power supply. If that state was OFF, the low voltage supply will not turned on at this moment.

The instrument controller then attempts to determine whether the unit is a UT340 (with front panel LCD and keypad) or a UT320 (no LCD , no keypad). If the LCD does not respond, the controller assumes that there is no LCD, and that therefore the instrument is a UT320. The UT320/UT340 status is then recorded in non-volatile memory.

When an SP0 or SP1 command is received, the controller checks to see if the instrument is a UT320 or a UT340, and will then ignore the SP1/SP0 commands, because those commands are not supported on a UT320, only a UT340.

To correct this error condition, a Master Reset must be performed.

To perform a Master Reset on a UT340 instrument:

1. Turn off the instrument using the rear panel power switch. Wait at least 10 seconds.

2. While holding the ‘F1’ key on the front panel, turn on the rear panel power switch.

3. Continue holding the ‘F1’ key for approximately 3 seconds.

4. Release the ‘F1’ key and press the ‘6’ key on the numeric keypad.

5. After approximately 8 seconds, the instrument will beep twice and the display will come up in pulser mode with all variables set to their minimum values.

6. If the ‘F1’ key is not held for at least 2 seconds, the instrument will continue with a normal power-up sequence.

7. If the ‘6’ key is not pressed within 3.5 seconds after releasing F1, or if any other key is pressed, the instrument will continue with a normal power-up sequence

The unit should perform a normal power up sequence with the LCD ON. You will hear a long beep.

The master reset procedure is also described in the UT320/UT340 Operations Manual. Click the link in Related Resources below.