MicroLogix 1100 with two RS232 ports

I am an experienced software engineer but somewhat new to PLC programming, and my question is mostly related to configuration/hardware.

I am updating an existing application which currently uses a ML1100 connected to a PanelView via the Ethernet port. I want to add the ability to commuicate with two external devices via RS232.

Can I use one 1761-NET-AIC to accomplish this? Basically, can I configure the PLC in RS-485 mode and connect to the AIC using the AIC's DH-485 port via a 1763-NC01 cable?

If this is possible and the two RS232 ports are addressable, i should be able to connect one external device using a 1761-CBL-PM02 and a DB9 serial cable...

Let me know if I am way off base here... any help is greatly appreciated!

This can work, only if the two external devices "speak" DH485. This is a protocol, not an electrical specification.

Can you tell us specifically what those external devices are?

OkiePC said:

This can work, only if the two external devices "speak" DH485. This is a protocol, not an electrical specification.

Can you tell us specifically what those external devices are?

Click to expand...

One device is a POS/receipt printer, to which I will send formatted ASCII string to print data.

The other is an external LCD display (7-segment LCD digits) , to which I will also send a formatted ASCII string to display data.

So what is some options for connecting two RS232 devices to a MicroLogix 1100?

Since the devices need ASCII, you may be able to configure the serial port for ASCII User mode, but then you need a way to connect all three devices and address the slaves.

I have seen some generic RS-232 to RS-422/485 devices work just fine, but then the devices need to be addressable at the other end.

We have a SLC sending DF1 data to four nodes using a 232/422 converter like this, but those devices are also configured and designed to accept the DF1 protocol. They ignore messages that are not prefixed with their own "address".

Some years ago, I used two display units on rs-232 sending them ASCII data through a RS-232 to RS-422 converter, but those displays were also configured to only look for their own address as a prefix to each message.

If you can post the full details of your slave devices, someone here may have a method.

Where there's a will (and a budget) there's a way.

Welcome to the forum, by the way. If there's a solution, this is likely the place to find it.

Paul

If you replaced the ML1100 with a ML1400, the 1400 has two serial ports.

Thanks Paul! Looks like I have some more investigating to do! Thanks for your help, Paul, I'm sure I'll have more questions as I dig into this project further...

Kris

Ken Moore said:

If you replaced the ML1100 with a ML1400, the 1400 has two serial ports.

Click to expand...

That might be the way to go. I was also looking at B&B's serial "smart switch" ( http://www.bb-elec.com/product11.asp?sku=232MSS2 ), but for the cost difference and simplicity (fewer cables, etc.) upgrading the PLC might be the way to go. Thanks Ken!

Another option, if you're not locked into using a Panelview, would be a Red Lion HMI. Lots of ports, and simple protocol conversion. I just finished a project with a handheld barcode scanner (via RS-232), vision system (via Ethernet), and PLC (via RS-485) all communicating with each other through a G306.



-Eric

I would join Erik for Red Lion.But using G3 so you can stay with your current HMI and use the 2 serial ports on the G3.
The G3 "talk"with the ML by Ethernet and communicate with the other devices by the other 2 serial ports and you still have another RS485 port.
Very easy to use and good support.

Arik brings up a good point. You could keep the PanelView, and just add a Red Lion 'Data Station Plus'. The 'LE' model has all the protocol capabilities (and ports) of their HMI, just without the screen. I haven't used one myself, but based on my experience with the G3 HMIs, this would 'fit the bill' nicely.

http://www.redlion.net/Products/Groups/DataStationPlus/DataStationPlus/Docs/07038.pdf

Their protocol conversion is easy to set up. Mapping tags between devices is just drag and drop. You can probably have your ML1100 talking to both devices in no time.



-Eric

Hi Eric, I'm working with Micrologix1100, Barcode scanner and Red Lion HMI G306...Can I get data from barcode with the HMI and store that in PLC??
Thank you

galonso099 said:

Hi Eric, I'm working with Micrologix1100, Barcode scanner and Red Lion HMI G306...Can I get data from barcode with the HMI and store that in PLC??
Thank you

Click to expand...

yes not a problem