You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > PLCS.net - Interactive Q & A > LIVE PLC Questions And Answers

Reply
 
Thread Tools Display Modes
Old September 15th, 2021, 08:29 AM   #1
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
Outputting numerical values from a sensor to PLC via DH-485

Some background: We have two assembly machines in house that make a part that gets crimped by deforming the top of a cylinder. We use a LVDT with some tooling to examine the step height from the top of the crimp to the next component that is captured by the crimp and our operators use gauge pins to examine the diameter all to ensure compliance within limits.

I want to install a 3D sensor to perform the checks. I have a few picked out that show promise. The issue is the current level of communication on the machines which is DH-485 (currently only between an HMI and PLC). We have SLC 5/03's installed with some remote I/O as well. The leading sensor candidate that we are considering to purchase uses ASCII protocol over either ethernet or serial communication.

How do I get actual values from the sensor to the PLC for display on the HMI? I spoke to our controls engineer yesterday and he thinks a 'Basic' module like 1746-BAS-T would likely have to be added to the rack to capture the data and communicate with the sensor.

The goal is for an operator to examine the HMI for maybe a running average of the crimp or a measurement history so that they would be able to tell if the tooling is hitting too hard or not hard enough.

The controls engineer was also considering the possibility of swapping the 5/03's for 5/05's and upgrading to ethernet. Is there an advantage to this other than speed?

If anyone has any suggestions please let me know. Any help is appreciated! My apologies in advance if I don't respond to questions directly. We're pretty busy here.
  Reply With Quote
Old September 15th, 2021, 08:43 AM   #2
pturmel
Member
United States

pturmel is offline
 
Join Date: Jul 2021
Location: Atlanta
Posts: 102
I've used the SLC Basic module. Very old-school but works. Converting to 5/05 would be nice, but doesn't solve your problem.


You might consider switching the SLC's channel 0 to user mode, but that will make programming a pain. Unless your programmer has the funky serial-to-DH485 interface (I don't remember that model #).
  Reply With Quote
Old September 15th, 2021, 09:14 AM   #3
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
Well it's good to know that the basic module is an option. Neither of us have used it before. I believe we do have the serial to DH485 converter. Just trying to figure out the best option for everything to talk.
  Reply With Quote
Old September 15th, 2021, 09:32 AM   #4
parky
Member
United Kingdom

parky is offline
 
parky's Avatar
 
Join Date: Oct 2004
Location: Midlands
Posts: 3,473
The Basic module is good for simple coms i.e. ascii, quite simple to program you do not have to buy the basic configuration software can be done with a terminal program, the basic config software is expensive for what it is.
  Reply With Quote
Old September 15th, 2021, 10:20 AM   #5
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
Good to know. I was just in the manual for the Basic module and saw that the programming software has it's own manual as well. Getting ready to peruse that to get an idea of what needs to happen.
  Reply With Quote
Old September 15th, 2021, 10:50 AM   #6
Helliana
Member
United States

Helliana is offline
 
Join Date: Nov 2011
Location: Louisiana
Posts: 759
All the 1746-BAS cards are obsolete and no longer being produced. I'm sure you can still purchase on the used/refurbished market, but that's just kicking the can down the road.



I would look into migrating to the CompactLogix family. You could use a 1769-ASCII or 1734-232ASC. In the compactLogix family, all the ascii programming is done in the PLC program, so it makes it much easier for a maintenance guy to troubleshoot or replace. You don't have take the card out and move jumpers around multiple times or load the BASIC program using PUTTY, Hyperterminal, or some other terminal software. You can use a 1747-AENTR if you want to keep your SLC Rack and I/O and not rewire. You will also gain ethernet connectivity, and it will all be cheaper than the retail price of a SLC 5/05. SLC parts are getting harder to come by and more expensive daily. I would take this opportunity to migrate for the future, especially if you already have a Studio 5000 software license.
  Reply With Quote
Old September 15th, 2021, 11:10 AM   #7
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
The remote I/O is the "Flex I/O" RIO adapter and several input/output cards and my understanding is that it is not compatible with the Compactlogix platform in which case we'd have to replace it adding a fairly significant cost to retrofitting. This is the main reason I'm asking about possibilities for communicating within the SLC platform.
  Reply With Quote
Old September 15th, 2021, 11:20 AM   #8
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
And to be clear, the vision sensor I'm looking at has ethernet I/P capability and that comm protocol would be preferred. I just didn't think they were compatible.
  Reply With Quote
Old September 15th, 2021, 11:25 AM   #9
Jim3846
Member
United States

Jim3846 is offline
 
Join Date: Dec 2019
Location: Cincinnati OH
Posts: 214
could go the route of upgrading to a compactlogix? replace all the racks rio with ethernet cards. convert the program to compactlogix program. Then you can use an up to date interface, but maybe this is too painful?
  Reply With Quote
Old September 15th, 2021, 11:42 AM   #10
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
It's a money issue where I'm at. IMO it would be preferable that the two machines be brought up to a more current platform. At some point a third machine will likely be built and although some of the hardware in the machine would likely be vastly different (Ethernet I/P valve & sensor modules vs. wiring come to mind), the PLC platform could at least be the same. They might be able to share spare parts at a minimum or something along those lines.

There was also concern about cycle time with DH485 (1.5-2s-ish) and recommended an accelerator unit that would help with saving time @ a cost of $3500ish. I'm thinking 4 1794-AENT's and a Compactlogix would eclipse that but perhaps not by much.
  Reply With Quote
Old September 15th, 2021, 01:47 PM   #11
Helliana
Member
United States

Helliana is offline
 
Join Date: Nov 2011
Location: Louisiana
Posts: 759
Quote:
Originally Posted by esp400 View Post
And to be clear, the vision sensor I'm looking at has ethernet I/P capability and that comm protocol would be preferred. I just didn't think they were compatible.

Moving to a SLC5/05 won't help that issue, since the SLC family only has limited explicit messages only support. You may could let a CompactLogix do all the sensor communication and message the needed values to the SLC until you get the money to complete the upgrade, but none of the new CompactLogix family have builtin serial ports to communicate back to the SLC easily.
  Reply With Quote
Old September 15th, 2021, 02:05 PM   #12
Engineerj22
Member
United States

Engineerj22 is offline
 
Join Date: Apr 2021
Location: NW Indiana
Posts: 35
replace the RIO flexheads with ethernet flexheads instead, keep the IO, switch to a compactlogix. How much IO is on the local slc?
  Reply With Quote
Old September 15th, 2021, 03:02 PM   #13
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
The local is a 7 slot rack. I agree. I think this and a Compactlogix is the way to go. Possibly with the adapter that will allow the Compactlogix to talk to the SLC rack that was mentioned.
  Reply With Quote
Old September 15th, 2021, 03:02 PM   #14
Ken Roach
Lifetime Supporting Member + Moderator
United States

Ken Roach is offline
 
Ken Roach's Avatar
 
Join Date: Apr 2002
Location: Seattle, WA
Posts: 16,049
Can you specify the 3D sensor so folks can examine what is serial and Ethernet protocol capabilities are ? Keyence, Basler, LMI Gocator, Cognex, SICK, IFM Efector... there's a few that come to mind.

The Channel 0 serial port on the SLC-5/03 and the string instructions in the SLC operating system can handle simple short (<82 char) strings of data.

In my opinion the 1746-BAS (or its sorta-modern successors, the Prosoft MVI46 modules) are mostly valuable for legacy support and heavy-duty hardware.

My first instinct is to go for a more modern middleware device that can handle both the 3D sensor's protocol and the SLC's data table access commands over DF1 protocol to the SLC's Channel 0 serial port. This could be a Raspberry Pi running Node-Red or Python, or a Red Lion DataStation, or a Hilscher or HMS gateway device, or something else.

I would start by establishing exactly what the 3D sensor offers: ASCII data sent as human-readable strings ? EtherNet/IP cyclic adapter functionality ? Emulation of ControlLogix tags ?
  Reply With Quote
Old September 15th, 2021, 03:07 PM   #15
esp400
Member
United States

esp400 is offline
 
esp400's Avatar
 
Join Date: May 2015
Location: Milwaukee
Posts: 69
Ken,

The sensor we are looking at is the LMI 3500 series snapshot sensor. The manual simply says that it is capable of ASCII over ethernet or serial communication.

From the manual:

"The ASCII protocol is available over either serial output or Ethernet output. Over serial output,
communication is asynchronous (measurement results are automatically sent on the Data channel
when the sensor is in the running state and results become available). Over Ethernet,
communication can be asynchronous or can use polling. For more information on polling
commands, see Polling Operation Commands (Ethernet Only) on the next page."
  Reply With Quote
Reply
Jump to Live PLC Question and Answer Forum

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Topics
Thread Thread Starter Forum Replies Last Post
Omron plc junk values Ltpriyank LIVE PLC Questions And Answers 2 July 28th, 2021 03:55 AM
Advice for connecting ground of RS 485 in PLC arbj LIVE PLC Questions And Answers 6 October 10th, 2015 02:30 PM
Red Lion HMI to SLC5/05, values stop writing to PLC AutomationTechBrian LIVE PLC Questions And Answers 0 September 24th, 2015 08:32 AM
Help with DF1 Protocol command to retrieve N7 integer values from Micrologix 1200 PLC davidgay LIVE PLC Questions And Answers 7 June 28th, 2002 08:59 AM


All times are GMT -4. The time now is 08:53 AM.


.