Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 63)

Publication 1753-UM001C-EN-P - March 2010 63
Wire the GuardPLC 2000 Controller and I/O Chapter 5
Unused analog inputs must be short-circuited. Place wire jumpers to
ground on any inputs that are not used.
High-speed Counter
Module (1755-HSC) The 1755-HSC module features inputs for high-speed counting up to 1
MHz. These counters are 24-bit, and are configurable for either 5V or
24V DC. The counters can be used as a counter or as a decoder for
3-bit Gray Code inputs. As a counter, input A is the counter input,
input B is the counter direction input, and input Z is used for a reset.
The counter inputs must be connected by using shielded, twisted-pair
cables for each measurement input. The shields must be connected at
both ends. The input lines should be no more than 500 m (1640 ft) in
length. All reference (L-, C-, or I- depending on the controller)
connections are interconnected on the module in the form of common
reference pole.
Cables are clipped to the shield-contact plate when connecting
counter inputs. See the instructions for connecting shielded cabling to
the shield contact plate on page
48
To be sure that counters are used in a safety-related manner (SIL3 in
accordance to IEC 61508), the whole system, including connected
sensors and encoders, must satisfy these safety requirements. Refer to
the GuardPLC Controllers Safety Reference Manual, publication
1753-RM002 , for more detailed information.
10
11
12
13
14
15
16
17
18
I-
I6+/2-
I-
I7+/3-
I-
I8+/4-
I-
I5+/1-
Wire
Jumper
1755-IF8
IMPORTANT
D
Do not terminate unused high-speed counter inputs.