Rockwell Automation 57C421B Pulsetach Input Module/DCS 5000/AutoMax - Manual (Page 13)

2Ć5
The module provides three external digital inputs which are enabled
through software (see register 6). Each input causes the module to
perform a specific function at the occurrence of an external signal
on that input as shown below:
D Origin Clear Input Ć Reset the counter
D External Latch Input Ć Read the counter
D External Count Stop Input Ć Stop the counter
The module's digital input circuitry is shown in figure 2.4.
OUT
DIGITAL
FILTER
+5V
464W
4.3V
330W
INPUT
COMMON 7
6
TO EXTERNAL DEVICE ORIGIN CLEAR INPUT
OUT
DIGITAL
FILTER
+5V
464W
4.3V
330W
9
8
TO EXTERNAL DEVICE
EXTERNAL LATCH INPUT
OUT
DIGITAL
FILTER
+5V
464W
4.3V
330W
11
10
TO EXTERNAL DEVICE
EXTERNAL COUNT STOP INPUT
Note that all channels are individually isolated.
TERMINAL
TERMINAL
TERMINAL
ORIGIN
ORIGIN
EXTERNAL
LATCH
INPUT
EXTERNAL
LATCH
COMMON
EXTERNAL
COUNT
STOP
INPUT
EXTERNAL
COUNT
STOP
COMMON
Figure 2.4 Ć Module Digital Input Circuitry