ION7650 Sag/Swell alarm into a Modbus Register

[solutions_iems-]

I have two ION7650 on 11kV supplies.

My client wants to know when a sag or swell waveform capture has occured in the meter by receiving a notification in the site BMS using a Modbus register as the trigger.

Using Designer, I have looked at a Modbus Slave module linked to the output of the Sag/Swell module (DistState) to change the value in the slave register from 0 to 1 (Packed Boolean). Will the Manual Waveform Trigger in PME simulate an output on the Sag/Swell module?

Is this the best way to go about this or is there a better solution?

[Tom_Stevenson · Accepted solution]

Hi

A manual waveform trigger won't stimulate a sag/swell output, but one idea would be to pulse merge a manual waveform trigger with the sag/swell output and link that to a counter module.  The counter module output can then be exposed to modbus which helps prevent any sags/waveforms being missed by a polling approach (the counter is the absolute number of changes).

BR

Tom

[Charles_Murison · Accepted solution]

One way I have also seen this done is linking the Sag/swell count to a modbus register, then BMS system is configured to recognize a change in value to indicate a sag or swell. Another option would be to link the sag/swell end pulse to a one shot timer that can then be linked to a mobus register. Oneshot period would have to be greater than the modbus polling period. The sag/swell state could change values so fast the modbus poll could miss the event.