Modbus vacuum switch

[mrtweaver]

I was wondering if someone here would have a solution to a question that mgmt has come up with.

We have 3 big vacuum pumps and they are PLC programed to automatically come on and turn off as vacuum is required. I am looking into attaching this PLC to our scada network and monitor and display which pumps are on at any point in time. The other thing i would like to do is have some sort of guage that displays the current inches of vacuum (Hg). The PLC only monitor 3 switches if no switches then only 1 pump, if 1 switch then 2 pumps and so on. This PLC and all the ones used on our scada network use modbus. So I am looking for somehting that commiunicates modbus ethernet that I can address using IP address that will supply the value so I can display it on the scada screens.

I know the one thing that would be easy would be attach into the PLC and put in some analog values and such then just monitor that way. But these proprietery PLCs are not exactly user friendly. So that idea is not the best especially since the maker of the pumps say that the plc does not support analog. It was all I could do to get the addresses that I will need to monitor.

to add another PLc would be another thing but I was hoping of something else. So any ideas are appreciated. Thank you.

 

[Singapore_Mats]

Some touchscreens can speak modbus, Proface is one.
You must find out of you circuit allow more modbus masters to be connected, screens are normally masters..

 

[mrtweaver]

Maybe in my haste I was not clear enough. We already have an OPC server (KepServer), we already have the SCADA software (Inductive Automation), We have our data collection PLC's on each machine (Horner), so far everything speaks Modbus. So what I thought was if there happened to be a vac pressure switch that would be accessable thru tcp/ip and prefer to talk modbus this way we would not have to purchase any more license from KepWare. The propietary PLC on the vac pumps does speak modbus thru the serial to ethernet convertor the OEM supplied and they also supplied the addresses I will need. So that is solved but since they only use switches to guess the pressure that means that my display that I will create will not show acurate pressure. That is why I wanted a vac pressure switch that will supply the value and I can read it via TCP/IP with a preference on Modbus communications.

Some touchscreens can speak modbus, Proface is one.
You must find out of you circuit allow more modbus masters to be connected, screens are normally masters..

 

[bkottaras]

Maybe in my haste I was not clear enough. We already have an OPC server (KepServer), we already have the SCADA software (Inductive Automation), We have our data collection PLC's on each machine (Horner), so far everything speaks Modbus. So what I thought was if there happened to be a vac pressure switch that would be accessable thru tcp/ip and prefer to talk modbus this way we would not have to purchase any more license from KepWare. The propietary PLC on the vac pumps does speak modbus thru the serial to ethernet convertor the OEM supplied and they also supplied the addresses I will need. So that is solved but since they only use switches to guess the pressure that means that my display that I will create will not show acurate pressure. That is why I wanted a vac pressure switch that will supply the value and I can read it via TCP/IP with a preference on Modbus communications.

Horner does Modbus but they also do analogue I/O. Can you add analogue modules to the PLC's?
What's proprietary about the Horner units?