Arceus

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Posts posted by Arceus



  1. Hello,

    I have a Micro850 PLC that has 5 2080-IF4 plug-in modules attached. Each of these modules are programmed to read 4-20 mA output signals from various sensors. It also has interlock switches connected to embedded digital input ports. When I download the program to the PLC from CCW, the message prompt that enables 'Remote Run' does not appear. I can't seem to switch the controller to run mode. Moreover, while connected, the I/O tags all read 0. I have tested the sensor wire leads with multimeter and they do give out output signals in the range of 4-20mA. Not sure why CCW is unable to read. The DI status LEDs also light up when I turn on the switches. I assumed that it might have to do something with the firmware, so I reset the firmware to default, that didn't help either. Any ideas on what the issue is or how to fix the issue? Thanks.

  2. Hello all,

    I am working on a project where I am communicating with a Mensor CPT6100 pressure transducer using a Micro-850 PLC. For this, I have used an AWA instruction to write some ASCII characters to the sensor. The sensor then responds to the write instruction by sending ASCII characters to the RX buffer and I used ACB and ARD instructions to read the ASCII characters. Now, I have set the ACB trigger type to 0 (msg triggered only once) and it successfully reads from the sensor. However, when I set the ACB trigger type to 1 (msg triggered multiple times), I do not get any reading in the ARD block. As a matter of fact, the ACB Q bit switches off every time the program is executed when the trigger type is set to 1. I am trying to get continuous readings from the sensor, but when the trigger type is set to 0, the program latches on to the first and only reading and it won't change. My question is, how can I change my program so that it can continuously and autonomously read from the sensor without me having to manually trigger the AWA and ACB instructions every time. I am attaching the program to this thread for your reference. 

    ASCII_Test_Copy.ccwarc


  3. 21 hours ago, ameyzingg said:

    Do you happen to have any kind of HMI/SCADA or input device to write values from computer to PLC?

    I don't have access to any HMI/SCADA or input device. According to this: https://literature.rockwellautomation.com/idc/groups/literature/documents/pm/1756-pm013_-en-p.pdf, I can use RSLogix to send ASCII strings to ASCII triggered devices such as MessageViewer Terminal using the AWA/AWT functions (by typing the hex code for the ASCII string in the input value field of the AWA/AWT). Can something similar be done to send ASCII commands from my computer to the pressure transducer via the PLC (Micro 850)? The only way the transducer responds with a pressure reading is when it encounters that command from the computer (I tried this with Putty and it worked, the transducer sent out ASCII text to the terminal for pressure reading). Btw, I am using a 2080-SERIALISOL plug-in module for serial port communication with the transducer. 


  4. I have been working on a PLC project that requires sending ASCII commands/queries to an external pressure transducer using the Micro 850 PLC (2080-SERIALISOL module) via serial port communication (ASCII protocol) and in response the PLC would read pressure readings from the transducer. I was able to write a ladder logic program that reads ASCII code from the transducer and converts it into string and inversely converts string output from the computer to ASCII and sends it to the transducer. However, I am uncertain as to how I should send the command string from my computer so that the external transducer receives it, recognizes it after the <cr><lf> is encountered and sends a pressure reading. Any suggestions as to how I can type in commands from my computer and receive responses from the transducer?