Comfortable&Relaxed
Member
Hi,
I'm investigating the feasibility of communication between a old PV standard display and a logix L5X controller via the controller serial port.
We have multiple PV standard units available in excellent condition, so this is a worthwhile use of an available (obsolete) resource if it is possible.
The PV's are type 2711-K10C3. The communication protocol for these is DH-485 (i.e. DH485 over an RS485 physical layer).
Work by others with a 2711-K6C5 (which has a RS232 physical layer but uses the DH-485 protocol protocol) has shown that the communication is possible using SLC mapping in the L5X to "trick" it into thinking it is talking to a SLC and configuring the com ports on both the L5X controller and the PV to DH485. Here is a link to the white paper: http://folk.ntnu.no/skoge/prost/proceedings/afcon03/Papers/048.pdf
The obvious caveats are that the serial port on the processor is no longer available for programming or configuration and that only one PV can be used per controller.
So, my question is this: can I simply use an 485 to 232 converter to bridge the physical layer difference? Would an old 1761-NET-AIC work for this?
I do not have a non-production controller to experiment with and I have no intention of risking damage to one of the ones we have running factory plant by experimenting.
Any comments or advice greatly appreciated.
I'm investigating the feasibility of communication between a old PV standard display and a logix L5X controller via the controller serial port.
We have multiple PV standard units available in excellent condition, so this is a worthwhile use of an available (obsolete) resource if it is possible.
The PV's are type 2711-K10C3. The communication protocol for these is DH-485 (i.e. DH485 over an RS485 physical layer).
Work by others with a 2711-K6C5 (which has a RS232 physical layer but uses the DH-485 protocol protocol) has shown that the communication is possible using SLC mapping in the L5X to "trick" it into thinking it is talking to a SLC and configuring the com ports on both the L5X controller and the PV to DH485. Here is a link to the white paper: http://folk.ntnu.no/skoge/prost/proceedings/afcon03/Papers/048.pdf
The obvious caveats are that the serial port on the processor is no longer available for programming or configuration and that only one PV can be used per controller.
So, my question is this: can I simply use an 485 to 232 converter to bridge the physical layer difference? Would an old 1761-NET-AIC work for this?
I do not have a non-production controller to experiment with and I have no intention of risking damage to one of the ones we have running factory plant by experimenting.
Any comments or advice greatly appreciated.