Rockwell Automation 1769-HSC Compact High Speed Counter Module - Manual (Page 21)

Compact I/O High-speed Counter Module 21
Publication 1769-IN030B-EN-P - October 2010
Transistor Output Transient Pulses
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.
Figure 9 illustrates that the duration of the transient pulse is proportional to the load current.
Therefore, as the on-state load current increases, the transient pulse decreases. Power-up
transients do not exceed the time duration for the amount of loading indicated at 60 °C (140 °F).
Figure 9 - Transient Pulse Duration as a Function of Load Current
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). The sudden application of voltage creates this transient
pulse. This condition is inherent in transistor outputs and is common to solid state
devices. A transient pulse can occur regardless of the controller having power.
Refer to your controller’s user manual to reduce the chance of
inadvertent operation.
On-State Load Current (mA)
Ti
me
- Durat
ion of T
ran
si
ent Pulse
(ms)