MVI71-MCM Master Polling Operation

MVI71-MCM Master Polling Operation

Ignore this post.

We are using a MVI71-MCM to communicate with serial devices on a RS-485 network and we are experiencing perodic communication errors. The error we are seeing is the slave device failed to reply. My question is related to understanding the communication failed timeout and retries. We have the timeout set for 500 msec and retries at 2. A protocol analyzer indicates a retry after 500 msec but the retry doesn't seem to wait much time before sending the next command. Below is an example of what I'm talking about.

28 15:05:18.466 G 03 06 1F 8F 00 05 7E 14
28 15:05:18.506 G 02 03 1C 52 00 1C E2 71
28 15:05:19.017 G 02 03 1C 52 00 1C E2 71

G indicates the status of the CRC check (B = bad)

Below is an extended listing from the analyzer.

I would expect the retry command to wait 500 msec for the reply. I also expect to see one more retry.

Is there any good write-up on how the MVI handles the command list?



28 15:05:17.324 G 02 03 1C 85 00 01 92 40
28 15:05:17.334 G 02 03 02 00 0B BD 83
28 15:05:17.384 G 04 04 00 00 00 55 30 60
28 15:05:17.575 G 04 04 AA 00 01 0E 10 0E 10 0E 10 25 35 26 25 0E 6B 0E 10 13 DD 16 0D 0D 5C 0E 1B 03 E8 0E 10 03 E8 00 64 00 00 00 05 07 D0 00 64 00 00 00 05 0E 10 00 8E 00 C8 03 52 00 00 21 ED 25 BA 00 01 02 FC 03 34 00 64 2A F8 00 00 27 10 00 01 00 00 00 00 0E 6B 00 01 00 00 00 01 00 00 00 01 00 00 27 10 00 00 16 07 0B F7 0B DC 00 A2 0C 04 26 43 26 5A 00 01 00 A1 00 A2 00 00 0E 15 03 34 00 00 00 8C 16 0D 0C 00 16 0D 0C 00 16 0D 0C 04 00 03 00 08 15 0D 22 69 13 EA FF FE 12 BC 13 8F 04 8F 03 7A 01 90 01 90 01 90 01 90 05 19 03 78 6C 10
28 15:05:17.615 G 04 02 00 00 00 A0 78 27
28 15:05:17.745 G 04 02 14 00 40 00 00 A0 00 00 00 00 08 1D 46 01 00 A2 3B 42 39 C0 41 28 11
28 15:05:17.785 G 05 03 13 88 00 36 40 F6
28 15:05:17.865 G 05 03 6C 49 B8 46 E4 0C B8 0D 93 09 BE 07 C3 08 0E 07 0E 04 CF 07 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 64 44 64 43 6E EE 6E ED 1B BB 1B BB 11 11 11 11 1D 72 1D 72 2E 13 2E 13 1D 72 1D 72 2E 13 2E 13 2A 3D 2A 3D 37 09 37 09 2A 3D 2A 3D 37 09 37 09 2B 16 2C B7 28 A0 28 CA 2A D4 2C 2C 1C FB 27 3F 29 84 24 E3 44 4A
28 15:05:17.915 G 05 03 05 DF 00 01 B4 B8
28 15:05:17.925 G 05 03 02 66 68 63 CA
28 15:05:17.965 G 03 03 1C 52 00 1C E3 A0
28 15:05:18.015 G 03 03 38 B4 00 46 59 D2 00 46 59 04 00 46 5A D6 00 46 59 62 00 44 8C DC 00 46 D3 64 00 46 86 EC 00 46 A3 2E 00 3F 22 04 00 42 70 04 00 42 70 4A 00 46 5A 60 00 42 88 50 00 41 0D 40 62
28 15:05:18.055 G 03 03 1C 86 00 05 62 52
28 15:05:18.095 G 03 03 0A 04 00 2D 7C 43 53 00 00 00 00 96 98
28 15:05:18.136 G 03 03 1D 92 00 03 A3 A8
28 15:05:18.166 G 03 03 06 00 02 00 01 00 02 91 D4
28 15:05:18.206 G 03 03 1D C4 00 08 02 7F
28 15:05:18.226 G 03 03 10 2E 27 41 0F E5 7E 46 59 00 10 46 A4 0D 33 3F 22 5B BE
28 15:05:18.266 G 03 03 1F 8F 00 01 B3 D7
28 15:05:18.346 G 03 03 02 00 3B 80 57
28 15:05:18.386 G 03 03 1C 85 00 01 93 91
28 15:05:18.406 G 03 03 02 00 0F 81 80
28 15:05:18.456 G 03 06 1F 8F 00 05 7E 14
28 15:05:18.466 G 03 06 1F 8F 00 05 7E 14
28 15:05:18.506 G 02 03 1C 52 00 1C E2 71
28 15:05:19.017 G 02 03 1C 52 00 1C E2 71