Table 3: I/O terminal blocks, functions, ratings, requirements, and cables
Terminal block
label
Terminal
label
Function, ratings, requirements Determine wire size
and maximum cable
length
Analog Input - Resistive Mode (0–600k
ohm)
Internal 12 V. 15k ohm pull up
Qualified Sensors: 0-2k ohm potentiometer,
RTD (1k Nickel [ Johnson Controls sensor],
1k Platinum, and A99B Silicon Temperature
Sensor) Negative Temperature Coefficient
(NTC) Sensor (10k Type L, 10k JCI Type II,
2.252k Type II)
See Guideline A in
Table 4.
Binary Input - Dry Contact Maintained
Mode
1 second minimum pulse width
Internal 12 V. 15k ohm pull up
See Guideline A in
Table 4.
ICOMn Universal Input Common for all Universal
Input terminals
Same as (Universal)
INn
Analog Output - Voltage Mode (0–10 VDC)
10 VDC maximum output voltage
10 mA maximum output current
Required an external load of 1,000 ohm or
more.
Note: The Analog Output (AO) operates
in the Voltage Mode when connected to
devices with impedances greater than
1,000 ohm. Devices that drop below
1,000 ohm may not operate as intended
for Voltage Mode applications.
OUTn
Analog Output - Current Mode (4–20 mA)
Requires an external load between 0 and
300 ohm.
Note: The Analog Output (AO) operates
in the Current Mode when connected to
devices with impedances less than 300
ohm. Devices that exceed 300 ohm may
not operate as intended for Current
Mode applications.
ANALOG
(Outputs)
OCOMn Analog Output Signal Common for all
Analog OUT terminals.
See Guideline C in
Table 4.
15FX-PCX2721 Expansion Input/Output Module Installation Instructions