Process Alarms

setpoing will be indicated.

Deviation Alarm:

Limit 4 has the capability to work either as process or as deviation alarm. This configuration is done during setup (look under SETUP). Also entered during setup is the alarm value. Programmed value is absolute and it works on negative as well as positive deviation e.g. if deviation alarm is set to 10, then output will get activated if process deviates –10 or +10 from the Setpoint.

Resetting Deviation Alarm:

Deviation alarm can be programmed to reset automatically or manually (non latching or latching). In non latching mode the alarm output will de-energize automatically when deviation drops below deviation limit value. In latching mode, the output has to be reset manually. For manual reset, first make the display indicate ‘dEVn Lt’ (for ‘Deviation Limit’) by pushing ‘DATA’ key successively (also look under ‘Process Alarms’). Next, while keeping the ‘DATA’ key pushed, go on to push the ‘RESET’ key. Deviation alarm will de-energize and the display will indicate so by displaying RLY RST. Selection of latching or non-latching mode for outputs is done during setup.

Displaying:

The DATA key is used for displaying Process Variable limits. Pushing the ‘DATA’ key sequentially brings up the display of limit 1 through limit 4 value. Display format is ‘PR LT1’ followed by the value of limit 1. Each consecutive push there after will display ‘PR LT2’ and programmed limit 2 value, ‘PR LT3’ and its value, ‘PR LT4’ and its value. If limits 3 and 4 are configured as rate and deviation limits respectively, then the third push will display ‘rATE Lt’ followed by rate value and the fourth push will display

‘dEVn Lt’ followed by deviation limit value. The programming of process limits is done during setup procedure (look under SETUP).

Resetting:

Once energized, alarms can be reset in two different ways --- automatically or manually (non latching or latching). In non latching mode the alarm outputs will de-energize on their own when the process variable drops below the limit value. In the latching mode they stay energized even if the process variable drops below the limit. To reset the energized outputs in latching mode, first make the display indicate the limit that needs to be reset e.g. ‘PR LT2’, by pushing the ‘DATA’ key (as described above under ‘Displaying’). Next, while keeping the ‘DATA’ key pushed, go on to push the ‘RESET’ key. The respective alarm output will de-energize and the system will indicate so by displaying RLY RST. Selection of latching or non-latching mode for outputs is done during setup.

Electro-Mechanical Relay Option

DPS3301 units can be ordered with either open collector outputs or electro-mechanical relays for process

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