Allen-Bradley 1747-SN - RIO Communication Retry Counter (M1:E.16 47); Retry Counter Example for Primary Devices

4–29Scanner Configuration and Programming
Publication 17476.6 - July 1996
M1 File Status Words 16 through 47 – indicate how many RIO
communication retries the scanner makes to each adapter on the RIO
link if communication problems occur. Each word (16–47) contains
a retry counter for each configured quarter logical rack (words 16–31
are for primary logical racks, 0–3, and 32–47 are for complementary
racks, 8–11). Retry counters are useful for troubleshooting
communication problems (such as electrical noise or poor
communication line connections) between the scanner and any
adapters. The scanner clears the retry counters when going from
Program to Run mode, Test to Run mode, and when going from
Program to Test mode. Note that the display (in words M1:e.16 –31)
of retry counters corresponds to the bits set in the Primary Logical
Device Address – Word 1 of the G file. Likewise, the display (in
words M1:e.32–47) correspond to the bits set in the Complementary
Logical Device Address – Word 3 of the G file.
Important: Your SLC control program cannot initialize/clear retry
counters.
Retry Counter Example for Primary Devices
The scanner’s I/O image tables are configured as shown with M1
status files displaying the corresponding retry counters:
ÇÇ
0
0123456789101112131415
ÉÉ
101
ÉÉ
10000
ÇÇ
1001
ÉÉÉ
001
Bit Number
Primary Logical Device Address, Word 1
G File - Primary
Specifies RIO
addresses for
primary logical
devices.
RIO Logical Rack 0
Starting Group
6 4 2 0 6 4 2 0 6 4 2 0 6 4 2 0
RIO Logical Rack 1
Starting Group
RIO Logical Rack 2
Starting Group
RIO Logical Rack 3
Starting Group
ÇÇ
ÇÇ
0
0123456789101112131415
ÉÉ
ÉÉ
100
ÉÉ
ÉÉ
10001
ÇÇ
ÇÇ
0001
ÉÉÉ
ÉÉÉ
100
Bit Number
Complementary Logical Device Address,
Word 3
G File - Complementary
Specifies RIO
addresses for
complementary
devices.
RIO Logical Rack 8
Starting Group
6 4 2 0 6 4 2 0 6 4 2 0 6 4 2 0
RIO Logical Rack 9
Starting Group
RIO Logical Rack 10
Starting Group
RIO Logical Rack 11
Starting Group
M1:e.16 – communication retry counter for RIO logical rack 0, group 0
M1:e.17 – not used in this example
M1:e.18 –communication retry counter for RIO logical rack 0, group 4
M1:e.19 – not used in this example
RIO Communication Retry
Counter (M1:e.16  47)