SLC 5/03 Pass through Comms

[Kabir]

I have a system that operates with one PV300 (near operator station) and a ML1200 in a panel some distance away communicating using DF1 over bluetooth serial. This ML1200 PV300 arrangement was put it to control one aspect of the machine, it is now required that more areas of the machine be controlled (simple on/off operations with some interlocks and timers). We already have a SLC A10 rack and PSU with I/O Cards (no processor) so I wanna install this near operator station to perform the new functions.

I was looking at the SLC5/03 line of processors and what I am thinking is Changing the Firmware of the PV300 from DF1 to DH485, connect the PV to the SLC DH485 via NET-AIC module and connect the ML1200 to SLC5/03 DF1 (since DH485 does not seam to work over the bluetooth link).

Problem: All my data for push buttons, parameters etc that are located in the PV for the ML1200 would have to be sent to the SLC then to the ML1200 via MSG instruction.

Question: Is there a way to have the PV communicate with both PLC's as if they were all on one network using passthrough? if so which processor would I need because the OS Firm etc thing for SLC always has me guessing.

 

[bguinn]

It might be worth changing the PV300 to a Redlion G3 which has many communication protocol capabilities.

 

[Ken Roach]

You have done some good research on this architecture and you have found the two basic isues: DH485 will not run through any kind of modem (including Bluetooth), and "Passthrough" in the SLC-5/03 controller only works in the DF1 -> DH485 direction, not the other way around.

While I find "use a different product" suggestions usually to be too glib, if you are expanding the complexity of your machine interface, a PanelView 300 (almost the smallest interface A-B makes) may be too small to do the job effectively. I know that some vendors offer terminals with multiple serial ports, which would allow you to connect to the MicroLogix 1200 via Bluetooth on one port and to the SLC-5/03 via DF1 or DH485 on another port. I have also done this with a PanelView Plus 700 terminal and a CF/RS232 adapter.

You could accomplish what you need using only a 1761-NET-AIC adapter as well.

1. Convert the PanelView 300 terminal from DF1 (RS232) to DH485 (RS232). This is not fully supported by Allen-Bradley but I have done it using the PanelView 300 Micro.

2. Connect the PanelView 300 to the SLC-5/03 Channel 1 DH-485 network port using a 1761-NET-AIC and a 1761-CBL-AS03 or -AS09 (or equivalent) cable.

3. Take the logic out of the MicroLogix 1200 and put it into routines in the SLC-5/03. Write MSG instructions to send the Inputs and Outputs from those routines to the MicroLogix 1200 via the Channel 0 RS-232 DF1 port and the Bluetooth wireless adapters.

Some of this functionality depends on the functions you are running in the MicroLogix 1200 controller. You may be able to move all or only some of the logic to the SLC-5/03. The MicroLogix may still have to perform some local or shutdown-in-the-event-of-communcations-loss functions on its own.

 

[Kabir]

Ken Roach to the rescue!

Thanks for your input on the matter, well i've considered what you are saying with respect to the communicating with the micrologix 1200 and the PV300 via MSG instructions in the SLC. I did the micrologix program to be independent initially its just simple ON/OFF request and some float parameters that would have to be sent to it for it to operate well.

Most of the functions the operator has to perform are done from switches that would be wired to the SLC so the small size of the PV300 is not a problem. It would more be used to calibrate the encoder and adjust machine timers etc from time to time.

So if what your saying is true, that passthrough would only would from DF1 > DH485 then even if I purchase a SLC 5/03 with pass through I would still have to route all my data through the SLC via MSG instructions then perhaps I should go with a SLC 5/03 (1747-L531) that I already have. what do you think?