Scanner test mode operation – Rockwell Automation 1747-DSN DISTRIBUTED I/O SCANNER User Manual
Page 34
Chapter 4
Operation and Troubleshooting
4–4
The scanner test mode operation is different for the 7 I/O block and 30 I/O
block configurations.
30 I/O block Configuration
For the 30 I/O block configuration, the Number of I/O Blocks and
Configuration Data Valid bits will operate in test mode in the same manner
as they operate in run mode. When entering test mode from program mode,
the scanner begins communicating with the I/O blocks when the bits for
Configuration Data Valid and Number of I/O Blocks are set.
Once in test mode:
•
the scanner sends the I/O block inputs to the SLC processor
•
the Communication Status Word is valid
•
the I/O block outputs are reset to 0 at all times
7 I/O block Configuration
For the 7 I/O block configuration, the Number of I/O Blocks and
Configuration Data Valid bits will not function until the SLC processor first
enters run mode.
If test mode is entered from program mode:
•
the scanner will not communicate with any I/O blocks,
•
the scanner will not send I/O block inputs to the SLC processor and
•
I/O block outputs will not be affected.
To enter the test mode and have the I/O blocks communicating with the
scanner, the SLC processor must first enter run mode and then enter test
mode. When entering test mode in this manner:
•
the scanner will be communicating with the I/O blocks
•
the scanner sends I/O block inputs to the SLC processor
•
the I/O block outputs are reset to 0 at all times
•
the Communication Status Word is valid
!
WARNING:
When entering run mode for the purpose of testing, I/O block
outputs will reflect the SLC processor output image. To ensure
the I/O block outputs do not inadvertently energize when entering
run mode, either make sure that the SLC processor output image
is zero or disconnect the scanner from the DIO Link. After the
SLC processor is put into test mode, the output image can become
non–zero and/or the scanner can be reconnected to the DIO Link
without the I/O block outputs turning on.
Scanner Test Mode
Operation