Dwyer DPM - Manual (Page 36)

Particulate Monitoring Systems
Installation & Operating Manual
Document No. 210-1003-M Page 29 ©2007
8.6 Process Running Signal
A process running signal indicates to the control unit whether the main process fan is ON or OFF.
Connection of a process running signal adds the following capabilities to the automatic self check
subsystem:
1. Sensor cable check – reference section 8.4 for further details.
2. Automatic system zero – verifies zero of the total system electronics, cable and sensor while fully
installed in the process.
For proper operation the following conditions must be met:
1. A process running signal must be connected to the control unit process run relay input channel.
This signal must be provided from an isolated, non-powered relay contact that closes when the
main process fan is on, and opens when the main process fan is off. A motor starter auxiliary
contact and/or separate control relay are typically used to provide this signal to the control unit.
Refer to the installation drawings for details on making connections to the relay input channel.
2. The process run relay input channel must be enabled for use. Reference menu #2 setup tree for
complete details.
8.7 Monitoring Self Check Status
There are four independent methods to monitor the status of the self check subsystem.
LCD Display
The control unit’s LCD display will indicate the current status of the self check subsystem as listed
below:
PV Units Display Indication
‘pA’ or ‘mg’ No self checks currently running. The most recent self checks were
successful, no failures
‘SC1’ Zero check in process
‘SC2’ Span check in process
‘ER1’ Zero error
‘ER2’ Span error
‘ER3’ Sensor error
‘ER4’ Cable error
‘ER5’ SRAM error
‘ER6’ Non-Volatile memory error
‘ER7’ Option board error
‘ER8’ Analog converter error
‘ER9’ System zero error