Migration MP200 to AC800M using AI880
We are going to migrate a MSG to 800xA for AC800M, these MP240 controllers have DSAI130 Analog Input with DSTAN001 Connection Unit, all the channels in MP240 are set at 0 to 1.25V and 0.25 to 1.25V. We are going to use a PM865 and some AI880. According with documentation I can see that this connection unit(DSTAN001) has a shunt resistence of 62.5Ohm, I'm not sure how is the signal coming from instruments. My question is, I can set the channel on AI880 to 0..20mA and 4..20mA and it's going to work? I guess because this CU has a shunt resistence.
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In general, analog inputs from field will be in the form of current signal (4-20mA), then a shunt resistor can convert into volage signals based resistance value. Even the currect input module shall have internal resistance to convert the current signal into voltage signal which is then converted into digital format. Ideally you have to match your AI module to field instrument signal type and its range. If your field instrument output is 4-20mA and range is 0-xx, AI880 with 4-20mA input and scale 0-xx settings should work correctly.