DL-06 comm port extravaganza

I hope that the Automation Direct users here on the forum can help me clear up some confusion I have about the number of communication ports available on the DL-06 controller. I'm usually an A-B user but a customer has specified this particular controller model.

I can see the Port 1 (the modular jack) is a dedicated purpose 9600 baud RS-232 port, and that Port 2 (the 15-pin connector) is a multipurpose port.

I need 3 Modbus RTU Slave ports and one Modbus RTU Master port in this system. The customer has said "sure, you can add as many as you want !" and I'm feeling dumb because I don't see any expansion serial modules for the DL-06.

I see the Ethernet, DeviceNet slave, and Profibus slave modules in the catalog.. but no expansion serial modules.

The modular controllers have the D2-DCM and D3-DCM, but those don't work with the DL-06, do they ?

The Anonymizer

Whoops, sorry, that was me posting. Didn't mean to appear so anonymous; my browser must be munching cookies tonight.

Eddie,

As far as I know the D2-DCM is a Modbus slave port only.

Port 2 of the DL-06 can act as a master or slave port. You can hang up to 99 slaves from the DL-06.

The DL-06 Port 1 can be used as a Modbus slave only.

Mike

Originally posted by
I need 3 Modbus RTU Slave ports and one Modbus RTU Master port in this system.

Click to expand...

Are you referring to the 'system' as a ONE DL06? Why do you need more than 1 modbus port?...

beerchug

-Eric

This customer wants to use the DL-06 as the CPU in several different "systems" (i.e. pump stations), including one that is a master to one other and a slave to three.

So that's one Modbus RTU Master port, and three Modbus RTU Slave ports, on one controller.

I know I can do what he wants with a DL-205, but he's got some inexplicable affection for the DL-06 and wants me to jump through hoops to use only that controller.

He is convinced that Modbus RTU Slave expansion ports are available for the DL-06, but I claim they're only available for the larger modular controllers. I'd hoped that somebody who knew the DL-06 better than I do (and I've combed the catalog) could say for sure.

Eddie Willers said:

He is convinced that Modbus RTU Slave expansion ports are available for the DL-06, but I claim they're only available for the larger modular controllers.

Click to expand...

Wait for Tom or Bernie to confirm this, but I tend to agree with your claim.

Better yet, have the customer SHOW you how you can get 4 MODBUS ports on an 06. Don't make any wagers though. He may have some trick up his sleeve...

beerchug

-Eric

Eddie,

Your customer wants to save money$$$ on hardware.

AD just dosnt make the DL-06 hardware for this. Call AD tech support and have them confim it in writing. That should settle this issue for your customer.

Considering how cheap AD is, I think that any fiddling around will soon spend more money in spent hours that you could ever save on hardware.

What is it that you and your customer really want to achieve ?

Why not use the ethernet module for the DL06 ?
Its dirt-cheap at 179 USD.

Very good idea jesper!

I think your customer may be confusing his objective with a possible solution. Have him clearly define the objective and the information sharing required, and let you define the solution that will accomplish that objective.

The second port on the DL-06 can be a Modbus RTU master or slave. You only get one per DL-06. I usually use this port 2 for networking, and port 1 for O/I and programming.

You can add lots of extra ports to the DL-205 using a D2-DCM. It can be a DirectNet master or slave but a Modbus slave only. Port 2 on most 205 CPUs can be a Modbus master or a slave.

I usually want a single network master. If I need to get info from one slave PLC to another, I simply have the master read it from the first and then write it to the second. If you start putting in redundant networks and all kinds of masters and such it quickly gets impossible to keep track of what is going on on your communications links, and your serial wiring gets pretty confusing too. I don't see much justification for having multiple master and multiple slave serial links.

And, of course, there is the ethernet solution. There the protocol takes caree of hiding the communications complexity, and you can be peer to peer.

I just recently had to recommend against using a DL-06 for this exact reason. I had a customer with an application that would be best implemented with 3 modbus ports (one master, two slave). The idea was this:

Master: read/write i/o from intellegent devices
Slave 1: Touchscreen
Slave 2: PC station master with HMI software.

The DL-205 could have done the job. But, around here we're ABB people. (No, you're not seeing double. That really is A-B-B). So, I got myself a little demo brick with a modbus module. It works like a champ. I've got blinkin' lights all over the place! Plus, I've got another port open if I wanted four.

In your case, you'll probably need to reconsider your network topology or insist on the DL-205.

AK