Allen-Bradley GuardPLC 1753, Safety Reference Manual

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34 Publication 1753-RM002C-EN-P - September 2008
Chapter 3 GuardPLC Controller and GuardPLC I/O Module Input Channels
The 1755-IF8 (AI module) can be configured as either eight
single-ended channels or four differential channels. No mixing is
allowed. The following input values are possible:
The following input values are possible for the 1753-IF8XOF4 module:
All of the channels default to voltage mode. On a channel-by-channel
basis, a shunt resistor can be added in parallel with the analog device
if current mode is requested. In current mode, the 10 K resistor
specified below is not required.
The 1755-IF8 AI module does not perform line monitoring. Therefore,
in the event of a wire break, an input signal continues to process.
In the event of an error line break, the input voltage floats and the
resulting value is not reliable. The inputs must be terminated with a
10 K
Ω
resistor parallel to the sensor. The internal resistance of the
source must be taken into account.
Input Values
Number of
Input Channels Polarity Current/Voltage Value Range In
Application
Accuracy
(5)
(5)
Accuracy is the guaranteed accuracy of the analog input without error reaction of the module. This value must
be considered when safety functions are configured.
8 single-ended 0…10V DC
0…1000
(1)
0…2000
(2)
(1)
With scale factor 1000 selected in RSLogix Guard PLUS! software.
(2)
With scale factor 2000 selected in RSLogix Guard PLUS! software.
1%
8 single-ended 0/4…20 mA
0…500
(1)(3)
0…1000
(1)(4)
0…1000
(2)(3)
0…2000
(2)(4)
(3)
By external 250
Ω
shunt.
(4)
By external 500
Ω
shunt.
1%
4 differential -10…10V DC
-1000…1000
(1)
-2000…2000
(2)
1%
Input Values
Number of
Input Channels Polarity Current/Voltage Value Range In
Application Accuracy
8 Uni-polar 0…10V DC 0…2000 2%
8 Uni-polar 0/4…20 mA
0…1000
(1)
0…2000
(2)
(1)
By external 250
Ω
shunt.
(2)
By external 250
Ω
shunt.
2%