Host Engineering Forum

General Category => Do-more CPUs and Do-more Designer Software => Topic started by: Henryp on August 10, 2017, 07:29:30 PM

Title: Modbus and Direct Logic
Post by: Henryp on August 10, 2017, 07:29:30 PM
Can a Do More speak both Modbus and Direct Logic protocols at the same time using the internal Ethernet port?
Title: Re: Modbus and Direct Logic
Post by: BobO on August 10, 2017, 09:47:19 PM
Can a Do More speak both Modbus and Direct Logic protocols at the same time using the internal Ethernet port?

Yes.
Title: Re: Modbus and Direct Logic
Post by: Garyhlucas on August 11, 2017, 11:01:21 AM
On the ethernet topic. Can you use the built in ethernet and the POM ethernet ports to keep company network traffic from slowing down remote I/O traffic?
Title: Re: Modbus and Direct Logic
Post by: BobO on August 11, 2017, 12:45:28 PM
On the ethernet topic. Can you use the built in ethernet and the POM ethernet ports to keep company network traffic from slowing down remote I/O traffic?

Absolutely. The ECOMLT is 'slow', but still plenty fast for most programming or HMI operations, so use it for that stuff and the built-in port for I/O. That has the added benefit of isolating the PLC from all of the enterprise network traffic, since the ECOMLT is a coprocessor. That virtually eliminates any possibility of the enterprise traffic negatively affecting the PLC.
Title: Re: Modbus and Direct Logic
Post by: Controls Guy on August 11, 2017, 02:03:04 PM
That has the added benefit of isolating the PLC from all of the enterprise network traffic, since the ECOMLT is a coprocessor. That virtually eliminates any possibility of the enterprise traffic negatively affecting the PLC.

Ooh, excellent tip!  Thanks!   :)

Same principle would apply with an H2-ECOM in a 205 DM application, correct?
Title: Re: Modbus and Direct Logic
Post by: BobO on August 11, 2017, 02:28:29 PM
Same principle would apply with an H2-ECOM in a 205 DM application, correct?

Yes. The ECOM has a little more power to affect things from the backplane than the ECOMLT does through the POM port, but in both cases the Ethernet copro is filtering packets. Keywords: copro and filter.

The nice part about the ECOMLT on BRX is price. Cheap insurance.
Title: Re: Modbus and Direct Logic
Post by: Controls Guy on August 11, 2017, 02:36:17 PM
The other place the low price comes in good is as a programming tool.  I have Hx-ECOM's for commissioning jobs where no Ethernet will ship with it, just so I don't have to program over serial, and $69 is a killer price to be able to do the same for BRX.  Less of an issue with DM's since there's the USB port, but still.  I've already bought an Ethernet POM as a shop tool (and used it on a non-E BRX project).
Title: Re: Modbus and Direct Logic
Post by: Garyhlucas on August 11, 2017, 02:37:03 PM
Thanks,
In the past customers have forced us to use addresses within their domain for remote access and they crashed the remote I/O running the waste treatment plant! So this will very useful.