Agilent Technologies 8453 User Manual, Installing And Operating Manual page 108

4 Using the Valve Unit and Valve-pump Controller
Servicing Your Valve System
Valve Unit Does Not Respond
When trying to switch the valve from the computer, the valve unit does not
respond. Either check the valve-pump controller or the valve unit.
Checking whether valve unit is functioning electrically:
1 Press the remote switch up at the rear of the valve unit valve unit to manual
2 If valve unit does not function, plug valve-pump controller-valve cable into
Checking whether valve-pump controller is functioning electrically:
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✔
✔
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operation and use the manual advance switch to operate the valve unit.
another channel of the valve-pump controller and use the manual advance
switch or, if your software allows it, operate the valve on another channel
with your software.
Check 5 V DC, 24 V AC lines on the valve connector of the valve-pump
controller. Replace fuses F1 or F2 in the valve-pump controller if necessary.
see Figure 41 on page 101.
Check the run line Run(-):
1 Open one of the connectors of the valve-pump controller-valve cable to
have access to the pins and plug the cable into the valve-pump controller
and valve unit.
2 Select a setpoint on your computer that is equivalent to the actual
position of the valve. The run line must be "1" now.
3 Press the remote switch up at the rear of the valve unit to manual mode
and use the manual advance switch to set the valve to the next position.
The run line must be "0" now, because the setpoint (from the computer)
is different from the actual position.
4 If the Run(-) line is defective replace the valve-pump controller.
Check the position line:
1 Disconnect the valve unit from the valve-pump controller.
2 Select a setpoint for position 8 on your computer.
3 Simulate a valve unit on the valve connector of the valve-pump controller
by shorting the position line with + 5 V (Pin 3,4) using a piece of wire.
(Encoder Bit 0, 1 and 2 are open, which simulates position 8). As soon as
the position line is pulled high, the run line Run(-) must be high.
4 If the Run(-) line does not respond replace the valve-pump controller.
Agilent 8453 Dissolution Testing System Installing and Operating Manual