We have a conveyor system with a Siemens S7-317 2DP with 3 DP/AS-i Link gateways (6ES7194-5AA00-0XA0). At one of the gateways we are getting the “AS-i Power Fail” led flicker.
The AS-i bus PSU is an IFM AC1206 (http://www.ifm.com/ifmuk/web/dsfs!AC1206.html).
The AS-i network from this gateway daisy-chains out to approx 20 nodes of IFM AC2701 (http://www.ifm.com/ifmuk/web/dsfs!AC2701.html).
At node 3 we have an isolator auxillary input on I+ and I1 and an IFM OC5230 (http://www.ifm.com/ifmuk/web/dsfs!OC5230.html) on I+, I- and I3 via wires 1, 3 & 4 of the sensor. This sensor and cable have been renewed to rule them out.
The DP/AS-i Link indicates “Slave 3” flashes the AS-i Power Fail led. We have seen the IFM PSU power led flicker which led us to renew it with a new IFM AC1208 (http://www.ifm.com/ifmuk/web/dsfs!AC1208.html) which just seem to freeze the DP/AS-i Link. This happened when we tried another AC1208. We tried a known-to-be-working AC1206 from one of the working gateways on this system which worked. The PSU is set to 115vac. This supply is constant.
The AS-i node has been renewed along with the DP/AS-i Link. The cables have been checked out between nodes - SY cable not yellow AS-i cable - the inputs to this node 3 have been disconnected which stops the fault. The fault only occurs when we have the OC5230 connected. We tried another sensor but after an hour or so the fault re-emerged. Without this sensor connected to this AS-i node the network is fine yet the system has been running previously without a hitch. The voltage at the node is a constant 29.6vdc.
Can anyone point me to something I may be missing or have overlooked, please?
Thanks in advance.