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Showing results for tags 'redundant cpu'.
Found 5 results
Hot Backup - L33ER Switchover for Redundant PLC
Krithik posted a topic in Allen Bradley / Rockwell AutomationDear Experts I have Compact Logix L33ER processor for Hot Backup Redundancy Purpose in WTP application. Iam using Flexlogix 1794-OB16 DO outputs. Flex adapter for IO communication. Iam trying for Soft Redundancy from main processor to peer and peer to main processor . During Switchover from Main to Peer and Peer to main Processor, the DOs are cut off. While in the middle of the process if the Switchover of PLC happens due to failure of Main or Peer PLC, if the DOs are cut off, Should i Start the process sequence logic from beginning? I tried configuring the DO properties of Communication Fail Behavior in output modules properties as "Hold Last Output but still the DOS are cut off during switchover. Then also Iam facing the problem of DO cutoff whle switchover. Iam having same program and IO configuration in main and peer plc generated through HotBackup tool. Please let me know if there is any way to Prevent DO cutoff while switchover . Also in Panelview HMI iam using 2 screens for Main and Peer PLC. While switchover the screens in HMI are showing in boxes. Please advise. Regards Krithik.K
ControlLogix and ControlNet unable to restart afer a fault
lost_in_space posted a topic in Allen Bradley / Rockwell AutomationHi, We have 2 x 1756-L71 Processors joined together with a pair of 1756-RM2/A redundancy modules. The rack also has 1756-EN2T and 1756-CN2R modules. I was called to the site after a power outage and found that the link between the 2 CPUs had failed with one displaying no program and the link modules with error lights. The ControlNet cards also had red lights on both channels and all of the FlexIO devices were red Xed in RSLinx. I went down the path of trying to get the CPUs up, and running but this was a red herring as I was informed that if the CPU's get out of Sync and have any faults on the cards the secondary one will lose its project. The ControlNet cards were giving a no Active Keeper fault? So we went down the path of the ControlNet cards, I initially thought that it was that the cards had lost their configuration files but we isolated the coax network to just the 2 cards, and the CP's and ControlNet cards came back up online. We joined the network back onto the ControlNet cards and found a faulty 1794-ACNR15/CFlexIO module. Once we replaced this the other devices (48 devices on the network) were not being discovered on the network. We went around and power cycled the IO units and then they started to Auto discover and the site came back up - Note CPUs were in Program mode at the time and I flicked them to Run and the site came back online. Does anyone have any information on why they needed to be power cycled and is there likely to be an underlying issue other than the single failed module pulling the network down?
S7-1500 redundant CPU hardware configuration
Jiggadoo posted a topic in SiemensI am building a redundant system using S7-1515R-2 CPU with TIA V16 version. Creating the hardware, there is not possible to insert any other card to the rack. Even power modules (PM) can not be inserted to the rack. How should I make the power feeding to the CPU. Should I use two power modules/devices or only one. How can I insert IO-cards to the system, is the only possibility to use Profinet IM-cards. In this system I am connecting the bus to the ring and using S2.
S71500R/H MRP ring to S7400 DP Master Connection
raynvd posted a topic in SiemensHello, does anyone know the best connection method between an S71500R/H profinet MRP ring (2 x S7 1500R controllers in redundant profinet ring) and an S7400 DP Master ?
S7-400H Redundant Confogration
ALI PLC posted a topic in SiemensDear Expert Is necessary to have both CPU (Master & Slave) same program blocks or only master PLC should have S7-program with blocks Best Regards Ali