acorn

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About acorn

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  1. Hi Wasan Thanks for your reply.  Yes I already had a look in the manual but I was a little confused.  Does this mean that %S6 (1 second) will pulse for 1 scan every 1 Second?
  2. Hi there Could anyone explain to me how these status bits work please? Fo instance %S6 is a 1 second pulse and %S7 a 1 minute pulse.  Do these just give a rising edge pulse after 1 second and 1 minute, or are they set for a full second / minute? Many thanks Acorn
  3. Thanks for the advice Bob, I wasn't aware of that.
  4. Hi everyone I would be grateful for some help please.  I am currently upgrading an old Modicon PLC to an Allen Bradley CompactLogix.  The existing software uses Grafcet for a large part of the program and I am using SFC in RSLogix 5000 (V24.0) to replicate this.  The problem I'm having is using the OSRI & OSFI instructions in the transitions between steps.  The first transition (Screenshot 1) uses a rising edge and the second (Screenshot 2) a falling edge.  I tried the following for the first transition 'NOT M[11] AND OSRI Local:1:I.Data.18 AND MW[144].0' but I cannot seem to get the syntax correct. I have worked around this at the moment by generating the one shot in my ladder code and referencing the result in the transition, but it would be a lot cleaner to learn how to do this correctly.  I would be grateful for any advice please as this is my first time using SFC. Thanks Steve
  5. Hi there Does anyone have any experience or advice on how to integrate an ANPR Camera into a PLC control system?  We are currently upgrading an Allen Bradley SLC500 to a CompactLogix system and our client would like the facility to read lorry number plates into the control system to allow automatic unloading of vehicles.  I've scoured the internet with no success.  Any advice would be gratefully received. Thanks Steve
  6. Thanks for your help guys I am installing a monitoring laptop this week that will be running Wireshark to try and capture some data that could help. I will also check the event logs on RSLinx and get the local electricians to check all of the ground practices. Thanks for your help, I will report back.
  7. Hi Guys I could use some help please with an SLC 5\05 problem that we are having. One of the sites that we maintain has 12 SLC 5\05 processors which are all connected via a fibre optic network over a distance of approximately 5 kilometers. The network was installed 9 years ago and has been functioning trouble free until a couple of months ago. The fibre converters are Hirschmann RS2-3TX\2FX and the fibre is multimode 62.5\125. There is no redundancy and the network is daisy chained straight through from the first to the last processor. Also on the network are 10 PC's running Wonderware Intouch SCADA, these communicate through two I\O ABTCP I\O servers. There are also 8 off PanelView Plus HMI terminals at various points throughout the network. We have recently had a strange occurrence where a number of PLC Ethernet channels appear to freeze up at exactly the same point in time. The green Ethernet LED goes solid and the processor loses all Ethernet communications to the SCADA PC's and to our maintenance laptop running RSLinx. The fault can occur on one or a number of PLC's at exactly the same point in time and each processor has to have its power cycled in order to recover from the fault and to re-establish comms. The control supply to the processors is derived from a number of separate High Voltage transformers and in some cases totally seperate electric board supplies as they are located at another site. This would appear to rule out a mains power quality problem. There appears to be no pattern to the problem. Any advice would be greatly appreciated. regards Steve
  8. Hi there, I would appreciate help with the following problem please; I have set up a DH-485 network in our office to programme a system before delivery to site. The network consists of an SLC 5\03 Processor, 2 off 1747-AIC Link Couplers and a 2711P-K6C3D PV Plus 600. Comms to laptop is via PCMK card. The network appears to be working correctly and I can access the SLC using RSLogix 500 from either end of the network. However when I attempt to connect to the PV+ I am getting no response. I created a new application in RSView Studio and download this to the PV+ via an Ethernet connection, this included a shortcut to my SLC and a driver for allowing the PV+ to communicate on DH-485, but I cannot get any comms between the SLC and PV+ or laptop and PV+ via DH-485. I tried adding drivers for DH485 and Serial DH485 under the 'Communications' tab in RSView Studio but neither seem to work. The PV+ came with a 2711P-RN3 DH-485 module factory installed, but with no driver for DH-485 in terminal settings. Is this correct? Only other clue is that I cannot get online addressing when creating tags in RSView Studio. Any help would be gratefully received!!!!! Thanks Steve