Petros Posted February 6, 2017 Report Share Posted February 6, 2017 Can anyone suggest how to connect an lcd (7-segment) large size (8 to 10 cm height) 4-digit numeric display on a V120 OPLC, just to broadcast the content of an MI? That is, when the FB (Num to BCD) is used, how does the 7 digit LCD communicate with the PLC? Thanks Petros Quote Link to comment Share on other sites More sharing options...
MVP 2021 Joe Tauser Posted February 6, 2017 MVP 2021 Report Share Posted February 6, 2017 You need four outputs per digit, so four digits is 16 outputs. You would use a NUM to Bits block to drive your coils. Your display should have four sets of 1,2,4, and 8 inputs. I've never used Num to BCD, and the Help is lacking a detailed example. It probably re-arranges the bits so they work with BCD displays. If it's important I'll load a PLC up and figure it out. Joe T. Quote Link to comment Share on other sites More sharing options...
Petros Posted February 6, 2017 Author Report Share Posted February 6, 2017 Dear Joe Thank you for your reply. Looking into it that is what I finally figured out. Therefore it is not worth the cost to engage 16 outputs just to read the content of a single MI. I will try and accomplish my task in a different way. Thank you for your attention. Petros Quote Link to comment Share on other sites More sharing options...
MVP 2021 Joe Tauser Posted February 6, 2017 MVP 2021 Report Share Posted February 6, 2017 It would probably be cheaper and easier to get a small HMI talking Modbus and just put the number on the screen. Joe T. Quote Link to comment Share on other sites More sharing options...
Cam Posted February 6, 2017 Report Share Posted February 6, 2017 Here is another option that I've seen using RS233 or 485 https://www.electronicdisplays.com/rs232-input-225-numbers ED202-111-4D-N1 Quote Link to comment Share on other sites More sharing options...
MVP 2014 Simon Posted February 6, 2017 MVP 2014 Report Share Posted February 6, 2017 Without having looked at the details, I would go with serial interface (RS232 or RS485). Usually they just accept a simple ASCII string and display the numbers. Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted February 7, 2017 MVP 2021 Report Share Posted February 7, 2017 I agree with go for serial. The extra cost of a dedicated panel like Cam suggests is often a far cheaper and better system than all the stuffing around and extra outputs needed for driving things directly. Been there, done that. In the old days I actually had to make the array from individual digits!! Aahhh..how I miss that....not! These days, youngsters are so spoilt! cheers, Aus 1 Quote Link to comment Share on other sites More sharing options...
MVP 2021 Joe Tauser Posted February 8, 2017 MVP 2021 Report Share Posted February 8, 2017 Remember thumbwheels? Joe T. 1 Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted February 9, 2017 MVP 2021 Report Share Posted February 9, 2017 Thumbwheels? I still use them for multiple input definitions on non-HMI plcs! Are we talking the same thing? You Yankees and yer funny words! cheers, Aus Quote Link to comment Share on other sites More sharing options...
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