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.

---------->>>>>Get FREE PLC Programming Tips

New Here? Please read this important info!!!


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

PLC training tools sale

Reply
 
Thread Tools Display Modes
Old May 16th, 2018, 05:20 AM   #1
legiopatrionostra
Member
Russian Federation

legiopatrionostra is offline
 
Join Date: Sep 2016
Location: Moscow
Posts: 3
Multistate Indicator in FactoryTalk View ME

Hi everyone!
Need yor help.
Normally we use Multistate Indicator for different values of ONE tag.
But is it possible to use one Multistate Indicator for several different tags? (I don't mean expression).

Example: I need to indicate statement of valve (CLOSED/OPENED). These signals are getting from limit switches. How to do:

If CLOSED = 1 then "State 0"
If OPENED = 1 then "State 1"

Thanks.
  Reply With Quote
Old May 16th, 2018, 05:28 AM   #2
cwal61
Member
United States

cwal61 is offline
 
Join Date: Jan 2011
Location: NC
Posts: 959
Use your limit switches to move a value into a DINT. Then use the DINT as Multi-state connection
  Reply With Quote
Old May 16th, 2018, 05:31 AM   #3
chopin
Member
United Kingdom

chopin is offline
 
Join Date: May 2012
Location: Milton Keynes
Posts: 106
I do not think you can connect multistate indicator to more than one tag.

What you could do is map your digital states to DINT type tag bits
So your valve closed = bit 0
valve opened = bit 1
Connect this DINT type of tag to multistate indicator and configure your states
State values will be like 0, 1, 2, 4, 8, 16, 32...
  Reply With Quote
Old May 16th, 2018, 04:30 PM   #4
GhostPepper
Member
Canada

GhostPepper is offline
 
Join Date: Mar 2018
Location: Ontario
Posts: 14
Think you may need to rethink your way of doing it, looks like it will be a problem to do it the way you say.
I’m assuming your setup is something like the below, if its not then please correct me.
  1. you have a valve that can be commanded to two positions (Open and Closed)
  2. you have two limit switches, one at each position, (Open limit switch and Closed limit switch)
  3. You want the Factory talk to display the position of the valve. (Open and Closed)

Your intended operation would be something like this:




  1. Start from Closed
  2. Valve is in the closed position.
  3. Closed limit switch is On.
  4. Open limit switch is Off
  5. Display state is “Valve Closed”
  6. Command to open
  7. Valve starts to move from Closed position to open position
  8. Closed limit switch is turn off.
  9. Open limit switch is still Off
  10. Display state remains “Valve Closed”
  11. Valve completes open command
  12. Valve arrives at open position
  13. Closed limit switch is still off
  14. Open Limit switch turns on
  15. Display State changes to “Valve open”


Essentially you want the display to show the position the valve last arrived at and remain in that state until the valve arrives at another position.
It is possible to set this up but I would not recommend it.

If you need to do it this way then how I would do it is to use another tag that holds the display state and have that tag set/reset or seal/unseal whenever the corresponding limit switches is turned on. Then have that tag drive the indicator.

Why it is not good: you have two limit switches that each can be two values High and low. This works out to 4 states:

State 0: Valve is in between positions
State 1: Valve is closed
State 2: Valve is open
State 3: Valve sensor is fail

In your method you are throwing away two of the states, that is good information you could have but just are throwing away.

What happens if the valve starts to slip and open a bit after closing, your display still says closed but really its partially open?
What if your limit switch gets stuck and you have them both on? Why not catch that error immediately?

cwal61 and chopin have it right, convert the sensor inputs to a dint state tag, use the states to drive the indicator.
  Reply With Quote
Old May 16th, 2018, 05:52 PM   #5
ASF
Lifetime Supporting Member
Australia

ASF is offline
 
Join Date: Jun 2012
Location: Australia
Posts: 2,571
You can do it, and it's just as easy as the OP suggested. You write an expression in the tag connection, and then you just have to get your syntax right.
Code:
If {[PLC_Shortcut]Closed_Tag} == 1 Then 0
Else if {[PLC_Shortcut]Open_Tag} == 1 Then 1
Else 2
Then set the multistate indicator so that state 0 shows closed, state 1 shows open, and state 2 shows in motion.
  Reply With Quote
Old May 16th, 2018, 07:58 PM   #6
VAN
Member
United States

VAN is offline
 
Join Date: Apr 2012
Location: Wa
Posts: 203
From memory, use a multi-state overlaying a momentary pushbutton.

The pushbutton triggers a value in the PLC (make sure to have a one shot) and the multi-state tied to if it's on/off.
  Reply With Quote
Old May 17th, 2018, 11:35 PM   #7
legiopatrionostra
Member
Russian Federation

legiopatrionostra is offline
 
Join Date: Sep 2016
Location: Moscow
Posts: 3
Quote:
Originally Posted by ASF View Post
You can do it, and it's just as easy as the OP suggested. You write an expression in the tag connection, and then you just have to get your syntax right.
Code:
If {[PLC_Shortcut]Closed_Tag} == 1 Then 0
Else if {[PLC_Shortcut]Open_Tag} == 1 Then 1
Else 2
Then set the multistate indicator so that state 0 shows closed, state 1 shows open, and state 2 shows in motion.
ASF, thanks!
Exactly what is needed!
  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
Error message IdealDan LIVE PLC Questions And Answers 7 December 11th, 2017 07:40 AM
FactoryTalk View Machine Edition Multistate Indicator Blink MSe LIVE PLC Questions And Answers 1 September 30th, 2016 09:51 AM
FactoryTalk View Studio - Multistate PB jrsnydley LIVE PLC Questions And Answers 4 November 19th, 2015 01:08 PM
FT View SE Editing Without License Mark Cole LIVE PLC Questions And Answers 9 November 22nd, 2014 08:03 AM
Migration Panel View Kristian LIVE PLC Questions And Answers 2 August 8th, 2014 11:32 AM


All times are GMT -5. The time now is 12:40 AM.


.