Function Codes
WBPEEUI240751C0 6 - 9
I/O Channel (FC 222, 223, 224, 225)
The I/O channel function codes allow for single channel mod-
ularity. In other words, one I/O channel function code reads
the input value or drives the output of one channel. Specifica-
tions are set on a per channel basis rather than on an I/O
group basis. The function codes provide addressing, startup,
execute (i.e., run time), override, simulation, and failure mode
operation specifications. The I/O channel function codes are
exception reporting function codes.
Tables 6-1 and 6-2 summarize some of the I/O channel func-
tion code capabilities. Refer to the Function Code Applica-
tion Manual for detailed function code descriptions,
specifications, outputs, and capabilities.
Table 6-1. I/O Channel Function Code Summary
FC I/O Purpose Normal Mode Output
222 Analog input Reads analog input
channel data.
Analog input value in
engineering units and the
channel status.
223 Analog output Sets analog output
demand value and
acquires output channel
readback data.
Readback analog output
value in engineering units
and the channel status.
224 Digital input Reads digital input
channel data.
Digital input state (0 or 1)
and the channel status.
225 Digital output Sets digital output state
and acquires output
channel readback data (if
applicable).
1
Readback digital output
state (0 or 1) and the
channel status.
NOTE:
1. Not all digital output channels support readback. This depends on the I/O block type (e.g.,
DOT-100 block does not support readback).
Table 6 -2. I/O Channel Specificat ions Summary
Specification Description
Function Code
222
(AI)
223
(AO)
224
(DI)
225
(DO)
Alarming Alarm state
••
High alarm (EU)
••
Low alarm (EU)
••