Allen-Bradley GuardPLC 1753, Safety Reference Manual

Page: 36 / 120

36 Publication 1753-RM002C-EN-P - September 2008
Chapter 3 GuardPLC Controller and GuardPLC I/O Module Input Channels
Block Diagram of Analog Inputs of the 1755-IF8 Analog Input Module
The illustration above does not represent the specifications of the
related module.
Counter Module
The items listed in the sections starting on page 36 apply to the
1755-HSC module and to the GuardPLC 1200 and 1800 system digital
counter input channels.
General
Depending on the parameters in the application program, the counter
can be operated as a fast up/down counter with 24-bit resolution or as
an encoder in the Gray code.
When used as a quick up/down counter, the signals of the impulse
input and the counter direction are necessary in the application. A
reset can be accomplished only via the user program.
The 1755-HSC module features 4- or 8-bit encoder resolution. In the
GuardPLC 1200 and 1800 controller, the encoder has a resolution of
3- or 6-bit. Reset is possible.
8 channels
MUX MUX MUX
12-bit resolution
ERR RUN
Logic
I1
I8
A A A
D
D D
T T
Logic
42925
I/O Bus