SIG IN Input This pin is used to connect to field sensor’s pulse output positive pin.
COMMON Input This pin is used to connect to field sensor’s pulse output negative pin.
You can also use this pin for the negative return of the FIELD PWR or
EXT BIAS.
EXT BIAS Output This pin is used with pull-up resistor supplied by the user. The open
circuit voltage of this pin is approximately 23 Vdc and can source up to 25
mA. This means that the pull-up resistor value must be no lower than
920 ohms.
This pin can also be a source of isolated power not to exceed the above
values.
You can leave the EXT BIAS pin un-connected if not required.
FLDPWR+ Output Positive source of power from connector TB2.
This pin is used to power field sensor(s) with +24 Vdc from the Series C
system, or optionally from an external power source.
When the source of field power is the Series C +24V system supply, the
negative terminal is tied to the Series C cabinet ground. Since the sensor
Table 6.1 TB1 signal definitions
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Pin name Input/output Description
signal common, COMMON(x), is used for the power return, the field
sensor is no longer isolated.
If more than one pulse input channel uses field power, the channels are
no longer isolated from one another because of the shared return at
pins COMMON(x).
FLDPWR+ 1 through 8 are electrically connected to each other on circuit
board. This means they are bussed.
