44
3.3.5 Temperature re-transmitter / set current output
Besides AI PID, stand PID control and on-off control, if the output is defined as current output, the instrument can also
retransmit PV (process value) or SV (setpoint) into linear current and output from OUTP. The precision of current
output is 0.2%FS. The corresponding parameters are set as below:
When CtrL=POP, PV is retransmitted to linear current, the instrument works as temperature re-transmitter. When
CtrL=SOP, SV is transmitted and outputted, and the instrument works as an set current output.
OPt is used to choose output type, generally 4
～
20mA or 0
～
20mA output.
Parameter InP, SCL, SCH, and Scb are used for selecting input specification, setting low limit or high limit of PV and
adjusting input.
For example, in order to retransmit temperature read from K thermocouple, range 0
～
400
℃
, to current 4
～
20mA, the
parameters are set as below: InP=0, ScL=0.0, ScH=400.0, OPt=4-20, and X3 or X5 linear current module is installed
in OUTP slot. When the temperature is less than or equal to 0
℃
, the output is 4mA. When the temperature equals
to 400
℃
, the output is 20mA. The upper limit of transmitter output can be high up to 110% of the range, which
means when PV is 0
～
440
℃
, output current is 4
～
21.6mA.