Internet PLC Forum

General => Technical support => Topic started by: can on June 11, 2007, 02:32:56 PM

Title: PLC to replace rheostat
Post by: can on June 11, 2007, 02:32:56 PM

Hi guys,

like to find out if 888+ can replace rheostat. Do I use the analogue output to connect to an external device to replace the rheostat?

Regards
Can

Title: Re:PLC to replace rheostat
Post by: support on June 11, 2007, 05:27:32 PM

Except for T100MD1616+, all analog output on T100MD+ or T100MX+ PLCs are 0-5V with 8 bit resolution. The output however is high impedance and not meant for driving low impedance load. You could connect the 0-5V to your external device if it accept 0-5V reference voltage. Otherwise you need an amplifier circuit in between to convert the output voltage into other range.

T100MD1616+ has 1 channel of analog output that is 0-20mA. You can use a 250 ohm resistor to convert to 0-5V or 500 resistor to convert to 0-10V and it can drive up to 20mA current at full scale.