Mark VIe HMI Honeywell DCS modbus TCP/IP

Mark VIe HMI server and Honeywell DCS server(Mark VIe HMI-server,Honeywell DCS-client)are separated by a firewall cisco ASA5512.The client can ping the server but server cannot ping the client as per the rule in firewall.Is it possible to communicate them on modbus TCP/IP?Is it mandatory for server also to ping the client for modbus tcp/ip?
 
Because the client is the device that initiates the TCP connection, I don't believe the server needs to be able to ping the client. Just think about how you access web sites from a PC to the internet. Your computer can ping the web site, but the server hosting the web site cannot ping your computer.

However, you do need to also ensure that your firewall is not blocking the Modbus TCP port (502 by default).
 
Because the client is the device that initiates the TCP connection, I don't believe the server needs to be able to ping the client. Just think about how you access web sites from a PC to the internet. Your computer can ping the web site, but the server hosting the web site cannot ping your computer.

However, you do need to also ensure that your firewall is not blocking the Modbus TCP port (502 by default).
i too had the same thinking.is there any simulation software which can confirm this connection ? i dont have access to job site right now.
 
There are several Modbus simulator packages available.

WinTECH has both a master and slave called ModScan and ModSim: http://win-tech.com/

Simply Modbus also makes both master and slave simulators: http://www.simplymodbus.ca/

Witte Software also has both, with Modbus Poll and Modbus Slave: https://www.modbustools.com/download.html

All of the above are paid software, but have demo versions available that should be sufficient to confirm that the connection succeeds.
 
Well thanks for the reply.There are options of modbus and OPC both in the server of Mark Vie .But without taking too much pain ,we want modbus communication to act
 
sk1984,

I think you would find (or will find if you do more research and ask more questions) that the OPC option is much better than the MODBUS option, and will be less painful in the long run.

While I believe that both options require adding signals to the EGD in the Mark VIe to get them to the HMI (if you're going to use the HMI for MODBUS), if you want to use the MODBUS option of the Mark VIe directly (through a PSCA or the USCx if that's even still an option these days) that getting signals on the Mark VIe "direct" MODBUS is a lot more painful.

As with all standards, every OEM has their own interpretation--GE is no different with either OPC or particularly with MODBUS.

I would rather put my efforts into the OPC communication than trying to make MODBUS work--either via the HMI or the Mark VIe "direct" method and having to do work in both ToolboxST and on the HMI. I believe with OPC you can get time-tagging--which you can't with MODBUS, HOWEVER the time-tagging will be from the HMI not from the Mark VIe--but if the UDH uses NTP (time synchronization) at least you have a good chance that the time tags will be very, very close, whereas with MODBUS you ain't got nuthin' for time tags.

Anyway, I may be wrong about all of that--but that's my recollection of OPC versus MODBUS. And, hiring an experienced control system integrator that has worked with GE HMIs before, and Mark VIe, will put you that much closer to your goal of painless implementation (though GE can ALWAYS be counted on to throw a monkey wrench in the works with some perversion of a change that is undocumented (OH--sorry! all changes by GE are undocumented...!)).

Food for thought, and if we're lucky Faustojc or Demigrog will provide a few more details--correcting me if I'm wrong.
 
It is somewhat easy to set up an Mark VIe HMI to communicate via Modbus to the Honeywell HMI. The diagnostic tools on the Mark VIe HMI are MUCH better than the diagnostic tools on the PSCA or the controller. Additionally, you don't have to muck with the controller. You have to know a little bit on what your are doing with the Mark VIe HMI, but here I think the manual is someone sufficient.

However, back to your original question. 'Pinging' is ICMP based and really doesn't allow us to test if a particular TCP port is open. There are some tools out there to let you test if certain TCP ports are open, and that is what we need for Modbus communication. The firewall will have to have TCP port 502 (or 501 or whatever you configure) open so that both HMIs can talk back and forth. This is more of an IT question, but you may be able to get away with outbound only port 502 traffic if the Modbus connection is initiated from the inside...i.e. the Modbus slave is on the inside. However, you would need to test that to make sure.
 
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