Rockwell Automation 1746-XXXX SLC 500 4-Channel Analog I/O Modules User Manual - Manual (Page 60)

Publication 1746-UM005B-EN-P - June 2004
5-6 Testing Your Module
10. Repeat steps 1 through 8 for the remaining analog inputs.
11. If any of the analog input channels do not pass the start–up
procedure, check for the following potential causes:
•
The processor is not in the TEST/CONTINUOUS scan mode.
•
The terminal block is not secured on the analog module.
•
The analog module terminal block is not wired properly or
wires are broken. See chapter 3 for details on wiring the
analog module.
•
The analog module input channel sensor (or test voltage or
current source) is not operating properly.
If a current source is not available to test a current input channel, a
test voltage can be applied to the current input channel to achieve the
input boundary conditions. In normal operation, a voltage source
should not be connected to an analog input channel in the current
mode. To determine the boundary conditions use the following
equation:
Voltage Input (V) = Current Input (mA) x 0.25
Testing Analog Outputs
Before testing the analog module output channels, the SLC 500 system
must be installed and tested according to the SLC 500 Modular
Hardware Style User Manual (publication 1747-UM011) or the SLC 500
Fixed Hardware Style Installation & Operation Manual (publication
1747-6.21). The processor must be connected to a programming
EXAMPLE
If the current input boundary conditions are 1 mA
and 5 mA, the boundary conditions in volts would
be 0.25 volts and 1.25 volts. If this calculation is done
correctly, the test voltage should never exceed 5
volts.