V0N_hydro
Member
I have a panel in front of the equipment with a PanelViewPlus 7 standard with Factory Talk ME and a Factory Talk SE HMI up in the control room.
When the local-remote switch at the equipment is in Local the SE HMI should not be able to write to any setpoints in the PLC (1756-L73).
When the local-remote switch at the equipment is in Remote the SE HMI can write to the setpoint tags. maybe the ME HMI can't write to the setpoints in Remote but I am less concerned with locking out the local touchscreen HMI in Remote. Mainly I want to lock out writing from the SE HMI when the machine is in Local.
The catch is the program is using the Rockwell Process Library Plant Pax blocks P_Din, P_Dout, P_Ain, P_Aout so a single tag of AOI type has all the members for enabling and disabling alarms, setting CVs to manual override, changing targets and setpoints, etc.
I could build the SE and ME HMIs to read and write different AOI tags and then select the appropriate tags in the program based on the local/remote switch, but that would be another instance of a plant pax block with a hundred parameters for each IO point which seems like a pretty verbose and heavyweight solution, although relatively straightforward and easy for anyone to understand.
Maybe there is some trickery that can be performed by changing the Cfg_Area parameter in the Plant PAX blocks. It is a local block tag but with external access read/write. Then through some other Factory talk trickery only user logged in from the ME terminal has permission to write to the tags when they are part of the "local" area.
It also looks like Factory Talk Security can be configured in RSLogix, so I could prevent tag values from being modified through a permission set, but I'm not sure how I would change the permission set to exclude one HMI terminal or the other based on the local/remote switch.
Any suggestions on the most straightforward way to accomplish this would be appreciated.
When the local-remote switch at the equipment is in Local the SE HMI should not be able to write to any setpoints in the PLC (1756-L73).
When the local-remote switch at the equipment is in Remote the SE HMI can write to the setpoint tags. maybe the ME HMI can't write to the setpoints in Remote but I am less concerned with locking out the local touchscreen HMI in Remote. Mainly I want to lock out writing from the SE HMI when the machine is in Local.
The catch is the program is using the Rockwell Process Library Plant Pax blocks P_Din, P_Dout, P_Ain, P_Aout so a single tag of AOI type has all the members for enabling and disabling alarms, setting CVs to manual override, changing targets and setpoints, etc.
I could build the SE and ME HMIs to read and write different AOI tags and then select the appropriate tags in the program based on the local/remote switch, but that would be another instance of a plant pax block with a hundred parameters for each IO point which seems like a pretty verbose and heavyweight solution, although relatively straightforward and easy for anyone to understand.
Maybe there is some trickery that can be performed by changing the Cfg_Area parameter in the Plant PAX blocks. It is a local block tag but with external access read/write. Then through some other Factory talk trickery only user logged in from the ME terminal has permission to write to the tags when they are part of the "local" area.
It also looks like Factory Talk Security can be configured in RSLogix, so I could prevent tag values from being modified through a permission set, but I'm not sure how I would change the permission set to exclude one HMI terminal or the other based on the local/remote switch.
Any suggestions on the most straightforward way to accomplish this would be appreciated.