Technical Bulletin for MTL5582:
Involving MTL5582 I.S. isolators and multiplexed PLC inputs which resulted in unstable readings.
The MTL5582 is a resistance to resistance isolator requiring constant sensor excitation from the receiver unit (or in this case the PLC analogue input card).
Once excitation power is applied to the output channel the isolator needs to stabilise at a final value, typically within 4% of its final value within 1 sec.
Multiplexer type analogue cards generally only switch power to each input channel when required and will not power the channel long enough for the connected isolators signal to settle,
hence the output signal may be unstable and the reading inaccurate.
Because of this MTL does not advise the use of MTL5582 isolators with multiplexed inputs.
See the attached revised data sheet.
Revised MTL5582 data sheet