I/O terminal blocks, ratings, and
requirements
Table 2: IOM3723 terminal blocks, functions, ratings, requirements, and cables
Terminal block
label
Terminal label Function, ratings, requirements
Determine wire size and
maximum cable length
Binary Input - Dry Contact Maintained Mode
0.01 second minimum pulse width Internal 16 V, 10K ohm pull
up
IN
n
Binary Input - Pulse Counter/Accumulator Mode
0.01 second minimum pulse width
(50 Hz at 50% duty cycle)
Internal 16 V, 10K ohm pull up
BINARY INPUT
ICOM
n
Binary Input Common
for all Binary Input (IN) terminals
Note:
All Binary ICOM
n
terminals share a common,
which is isolated from all other commons, except the
Configurable Output (CO) common (OCOM
n
) when the
CO is defined as an Analog Output.
Note:
For all Binary ICOM
n
terminals, BI is isolated from
the FC bus common.
See Guideline A in Table 3.
Cable and wire length guidelines
The following table defines cable length guidelines for the various wire sizes that may be used for wiring low-
voltage (<30 V) input and outputs.
Table 3: Cable length guidelines
Guideline
Wire size/Gauge and type
Maximum cable length
and type
Assumptions
1.0 mm (18 AWG) stranded copper
457 m (1,500 ft) twisted wire
0.8 mm (20 AWG) stranded copper
297 m (975 ft) twisted wire
0.6 mm (22 AWG) stranded copper
183 m (600 ft) twisted wire
A
0.5 mm (24 AWG) stranded copper
107 m (350 ft) twisted wire
100 mV maximum voltage drop
Depending on the cable and the connected
input device, you may have to define an offset
in the setup software for the input or output
point.
1.0 mm (18 AWG) stranded copper
229 m (750 ft) twisted wire
0.8 mm (20 AWG) stranded copper
137 m (450 ft) twisted wire
0.6 mm (22 AWG) stranded copper
91 m (300 ft) twisted wire
B
0.5 mm (24 AWG) stranded copper
61 m (200 ft) twisted wire
100 mV maximum voltage drop
Depending on the cable and the connected
input device, you may have to define an offset
in the setup software for the input or output
point.
C
See Figure 7 to select wire size/gauge. Use
stranded copper wire.
See Figure 7 to determine
cable length. Use twisted
wire cable.
N/A
Maximum cable length versus load
current
Use the following figure to estimate the maximum
cable length relative to the wire size and the load
current (in mA) when wiring inputs.
Note:
The following information applies to low-
voltage (<30 V) inputs only.
IOM3723 Input/Output Module Installation Guide
7
