Changing IP adress of connected device when online on ProFace/Telemecanique HMI

[Fredrix 3]

Is there any way to connect to another IP adress when the HMI is online? (I have to identical PLCs, and I want to switch between them in online mode)

[PdL 71]

If I understand correctly, you want the HMI to change connection from Device1 to Device2, but with either device the same application is used ? I guess you could define multiple hosts in the HMI, each their own IP, and copy the application pages and only change all host reference from device1 to device2, and when you change device you change to either application pages for device1 or 2. But, all application changes have to be made twice which is sensitive to making mistakes in the changes. Is the PLC connected to the HMI only to be connected to HMI and nothing else? In that case you could assign the same IP to each PLC and figure out a way to physically switch between PLC1 and PLC2, and the HMI wouldn't know a difference.

[Fredrix 3]

The PLCs communicate with each other and a SCADA system. This will be a redundant system, thats why there are to identical PLCs. Only one of the PLC is active at a time, and the panel shall only read/write from/to the active PLC The easiest would be if I could make som kind of script in the HMI who changes the IP adress of the destination PLC when PLC1 gets inactive/PLC2 gets inactive The HMI supports D-Script, anyone programmed in this before?

[PdL 71]

If it is possible to change a host IP adress "on the fly" yes that would be the cleanest solution. Is there a manual or help file of the HMI which holds information on system parameters which are available, and perhaps read/write possibilities ? Can't help you on D-script though.

[Fredrix 3]

I'm trying to find one... The ones I've found doesnt say anything about the system parameters

[tragically1969 0]

If its a bona fide redundant PLC system do the pair not act as one anyway, meaning they effectively have the the same IP address ?

[Fredrix 3]

No, they have different IP adresses. If they had the same IP adress, I would'nt need to change it in the HMI

[tragically1969 0]

Which PLC is it ? And how do you tell the HMI which variable to use on screen ?, you would have to do as PDL says and have 2 sets of everything !!

[Fredrix 3]

The PLCs are Omron CJ1M A bit in the PLC is used to determine which is active, in addition to that I want the HMI to switch to the other PLC when communication fails 2 sets of everything is not an alternative! The sollution I'm working on now is to use internal variables on the HMI and synchronize them with the correct PLC with a global D-Script running in background. Now I'm stuck at error handling, I need the HMI to stop communicate with a PLC when error occurs, and then move on to the next PLC, but I can't find the systemword/bit for communication error (in the HMI)

[PdL 71]

Can't you use a heartbeat pulse from the ladder logic ?

[Fredrix 3]

I need the HMI to close communications when error occurs, if it doesn't close communication it will begin to work extremly slow and a lot of communications errors will show up

[PdL 71]

So there are 2 actions. A. Detect comms error B. Close and re-open communications. If B is not part of the HMI capabilities, no point in looking for A, but if B is possible it doesn't matter how you detect A, as long as you have a condition to trigger B? That's why I thought of a heartbeat pulse.

[Fredrix 3]

3 actions: A: Detect active PLC and use in HMI IO Synchronize script B: Detect communication error C: Close/Open communications according to error/no error (and change active PLC if necessary) The HMI is capable of closing communication port, but I need to detect the communication error in my script, there's my problem...

[Fredrix 3]

Anyone know how I can detect communication errors in my script? Problem solved! I monitor the communication cycle time in my script, if the cycle time is over a given value, the script treats it as a communication error and deactivates that PLC Thanks for all comments/help/ideas! Edited 19 Dec 2007 by Fredrix

[PdL 71]

Good job! Very clever

[ahassan 0]

So now that you can detect network/communication error, how do you change your ip address on the hmi (while connected - online mode) from the faulty plc to the second presumed running plc?

I think this was your main question on this thread.