Troubleshooting Procedures
3.11 Erratic Input Signal
PS2 Troubleshooting Guide
26 Service Manual, 03/2017, A5E36661550-AA
● Put PS2 in Manual mode: from Auto, press button.
● Move valve with
or buttons.
● If false feedback signal is corrected by moving the valve, consider Non-Contacting
technology. Contact Siemens technical support for assistance: 1-800-333-7421.
● If false feedback is still present when moving the valve, verify:
● Slide bar is in proper location:
First, unlock slide bar: see Transmission Ratio/Slide (Page 49).
Move slide bar back and forth twice, then move slide bar to proper setup position (see
following):
– For rotary, slide bar = 90°.
– For linear valves with travel at 25 mm (1.0 inch) or less; slide bar = 33°.
– For linear valves with travel at 25 mm (1.0 inch) or more; slide bar = 90°
● Reinitialize PS2. See Initialization Procedure (Page 50).
There are two ways to identify if the input signal is causing the valve behavior. One is placing
a current meter in series of the 4 to 20 mA loop. The other is using the PS2’s display as a
current meter. This is found in diagnostic parameter "mA".
● While the positioner is exhibiting the problem, verify unit is in Automatic mode.
● Press and hold all three buttons for at least 5 seconds.
– The diagnostic parameter name can be found in the lower right corner.
● Press the
to advance through the menu.
● Go to Diagnostic parameter "mA".
– Observe the movement of the actuator/valve and compare it to what is displayed on
the PS2, or current meter. If the display is changing with the valve assembly, then the
input signal is the cause. An investigation of the control system/loop tuning is
suggested.
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