Rockwell Automation 1747-L40 SLC 500 Fixed Hardware Style - Manual (Page 37)

Chapter 1
Selecting Your Hardware Components
1–18
To reduce the possibility of inadvertent operation of devices connected to
transistor outputs, adhere to the following guidelines:
•
Either ensure that any programmable device connected to the transistor
output is programmed to ignore all output signals until after the transient
pulse has ended,
•
or add an external resistor in parallel to the load to increase the on–state
load current. The duration of the transient pulse is reduced when the
on–state load current is increased.
The duration of the transient pulse is proportional to the load impedance.
This is illustrated in the following graph.
0
On-State Load Current (mA)
1000
1
2
3
4
5
6
7
8
9
10
1 100 200 300 400 500 600 700 800 900
Duration of T
ransient (ms)
Time