Allen-Bradley SLC 500

2–27 Selecting Your Hardware Components
Publication 1747-6.2
Transistor Output Transient Pulses
This section applies to the following SLC 500 fixed I/O processors
and SLC 500 I/O modules that have transistor outputs.
Fixed I/O Processors I/O Modules
1747- 2
1746-OB8
1747-
L
2
0E
1746-OBP8
1747-L20G 1746-OV8
1747-L20L 1746-OB16
1747-L20N 1746-OBP16
1747-L30L 1746-OV16
1747-L40E 1746-OVP16
1747- 4
1746-OB32
1747-
L
4
0L
1746-OV32
For the SLC 500 products listed above, the maximum duration of the
transient pulse occurs when minimum load is connected to the
output. However, for most applications the energy of the transient
pulse is not sufficient to energize the load.
!
ATTENTION: A transient pulse occurs in transistor
outputs when the external DC supply voltage is applied
to the common output terminals (e.g., via the master
control relay). The sudden application of voltage
creates this transient pulse. (See the following graph.)
This condition is inherent in transistor outputs and is
common to solid state devices. A transient pulse can
occur regardless of the processor having power or not.
Duration of Transient (T)
Transient (I)
(On-State Load Current)
Current
Time