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dieter_k
@dieter_k
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Joined: Nov 22, 2024
Last seen: Sep 19, 2026
Topics: 0 / Replies: 6
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RE: S7-1500 diagnostics buffer "Distributed I/O: station failure" every few minutes

MRP is the ring protocol. Your line is now a physical ring with no ring protocol, so it is just a loop. Frames go round, devices choke, one drops, com...

4 hours ago
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RE: DeviceNet 1756-DNB error 91 bus-off a few hours after conduit rework

So the far end is open. Without the second terminator every frame reflects off the open end, the CAN controllers see error frames, the error counter i...

9 hours ago
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RE: S7-1500 diagnostics buffer "Distributed I/O: station failure" every few minutes

Draw the line for me. Which port of which device goes where, and what does the second cable run connect to at each end? Segment lengths too.

15 hours ago
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RE: DeviceNet 1747-SDN, nodes at the far end of a 300 m trunk drop at 250 kbps

23.6 V rules power out. The trunk's too long for the baud rate, that's all. Thick trunk limits are 500 m at 125 kbps, 250 m at 250 kbps and 100 m at 5...

23 hours ago
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RE: New ET 200SP station, IM 155-6 red ERROR, every module shows missing

Photo of the right hand end of the rail, after the last module. And the firmware number off the IM label. Firmware is rarely it, but post it anyway.

23 hours ago
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RE: DeviceNet 1756-DNB error 91 bus-off a few hours after conduit rework

E91 is bus-off, the CAN controller gave up after too many errors. Not a node. Was the terminating resistor at the far end refitted after the new trunk...

3 days ago