Rockwell Automation 1746-XXXX SLC 500 Digital I/O Modules Installation Instructions User Manual
Page 41
SLC 500 Digital I/O Modules 41
Publication 1746-IN027D-EN-P - December 2012
(8)
Fast turn-off modules (1746-OB6EI, 1746-OBP8 series B and later, 1746-OB16E series B and later, 1746-OBP16, and 1746-OVP16) provide fast
OFF delay for inductive loads. Comparative OFF delay times for 1746-OB8/1746-OV8 and fast turn-off modules; when switching Bulletin
100-B110 (24Ws sealed) contactor, are: 1746-OB8/1746-OV8 OFF delay = 152 ms; fast turn-off modules OFF delay = 47 ms.
(9)
Fast off delay for inductive loads is accomplished with surge suppressors on the 1746-OB6EI, 1746-OBP8 series B and later, 1746-OB16E series
B and later, 1746-OBP16, and 1746-OVP16 modules. A suppressor at the load is not needed unless another contact is connected in series. If this
is the case, a 1N4004 diode should be reverse wired across the load. This defeats the fast turn-off feature.
(10)
Surge current = 32 A per module for 10 ms.
ATTENTION: A transient pulse occurs in transistor outputs when the external DC supply
voltage is applied to the output common terminals (for example, via the master control relay).
This can occur regardless of the processor having power or not. For most applications, the
energy of this pulse is not sufficient to energize the load.
Refer to the SLC 500 Modular Hardware Style User Manual, p
, for more
information on transient pulses and guidelines to reduce inadvertent processor operation.
Specifications – 1746-OG16
Attribute
Value
(1)
(1)
Removable terminal block.
Voltage category
5V DC TTL Signal Input (sinking)
Number of outputs
16
Points per common
16
Voltage, operating (V DC to DC COM)
4.5...5.5V DC
(2)
50 mV peak to peak ripple, max.
(2)
TTL outputs are inverted (0...0.4V DC = low voltage = True = ON). Use a NOT instruction in your
ladder program to convert to traditional True = High logic.
Backplane current
consumption
5V DC
0.180 A
24V DC
0.0 A
Signal delay, max resistive load
On = 0.25 mA
Off = 0.50 mA
Off-state voltage
4.5...5.5V DC
Off-state leakage, max
0.1 mA
Load current, min
0.15 mA
Continuous current per point
24 mA