Ken Roach

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About Ken Roach

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  1. Commands Protocol

    The original A-B protocols for the PLC/SLC controllers are called "Programmable Controller Command Code", or "PCCC". The modern ControlLogix uses a set of commands they call "Common Industrial Protocol", or "CIP".    CIP's most common connection is over TCP/IP and Ethernet, but it's the same commands if it's transported by ControlNet or DF1 serial transports. Much of the CIP protocol and commands are published, especially for ordinary data access. But much of them are not.   You will get zero support from Rockwell Automation if you're trying to roll your own protocol to edit the controller user program.  
  2. Parameter 388 and 389 are meant to be used together, as the High and Low Word for the "Units Traveled" parameter in the PowerFlex 525. Did you increase the data size so you could read two 16-bit words ?   It would not surprise me if the drive won't respond to a 1-Word request for Parameters 388 or 389 separately. Parameters 388 and 389 use an unusual encoding scheme;  instead of literally being the high and low 16 bit Words of a 32-bit integer, they are the value to the left of a decimal point (388) and the right of the decimal point (389). The manual also suggests that you can't Write 388 or 389 unless the drive is stopped.
  3. 1756-EN2TR communication error

    If you are experiencing communication failures, you should condition your logic using the connection status of the remote I/O devices so that a "stale" value will not cause your system to malfunction.    I generally use a GSV instruction to read the EntryStatus value for a remote I/O module.   "Communication failure" is too general a complaint to diagnose.    Is the 1756-EN2T module firmware crashing ?   Is it losing connection to only one remote device ?  What is that remote device ?  Do you have any diagnostic ability on the switch ports or devices ports to determine if you have a cable or noise problem ?
  4. PLC5 to Controllogix Tricks?

    You definitely cannot control 1756 ControlLogix I/O modules with a PLC-5 controller.    You could leave the 1771 chassis in place with the RIO network cable, and convert to a ControlLogix CPU, using the 1756-DHRIO or 1756-RIO as your RIO scanner.     That would end up costing more in time and effort over the long run because you would have to convert and test your program with a 1771 I/O architecture, then change it to a 1756 I/O architecture later.
  5. Learning about MicroLogix 1500

    Is the Fault LED on steady red, or is it blinking (at about 1/sec) ?     A steady FAULT LED means an unrecoverable hardware diagnostic failure;  the PLC generally has to be replaced. A blinking FAULT LED means that the controller is simply faulted;  it might have drained the memory retention battery, or be reacting to being in a new hardware configuration, or something else.   For your comms, try sticking with the default MicroLogix settings when you press DCOMM and that LED comes on green.   19200/8/N/1 speed and framing, SLC-Ch0/MicroLogix device type, CRC error checking, DF1 Full Duplex.    That way you don't have to rely on Autoconfigure.    
  6. Generally the module that has been replaced by a 1734-ARM will be inhibited in the Controller Organizer. Instead, you have inhibited the entire 1734-AENT Adapter, so none of the modules should have an active connection. The red POINTBus status LED and the extinguished Network Status LEDs on the ARM and OW4 modules suggests to me that the ARM module has failed or there is another problem on the POINTBus assembly.
  7. Communication: PV +600 to SLC 5/03

    The old PanelView 550 has that "2" in the part number indicating that it has a DH485 network port only.   So it would have connected to the SLC-5/03's Channel 1 DH485 network port, either through an AIC isolator or just directly with the "AMP->RJ45" cable. If you had to stick with DH485, you could do it with a 2711P-RN3, or you could use the serial port driver version and use a converter like the 1761-NET-AIC or equivalent.   It's not great;   you can't test it on a Windows 7/10 PC because that driver ONLY works on the CE boxes. It's easier/better to switch to using DF1 Full Duplex, so that you can more easily connect a modern Windows PC to the SLC's serial port or the PanelView's serial port.   Yes, you have to unplug the PanelView to connect to the SLC-5/03, but unless you're fully geared up for DH485 with a 1747-UIC interface and some isolators, that's a reasonable compromise.
  8. SLC 5/03, 1747-KE & 1747-OA16

    By my recollection, the 1747-KE Series B modules could get their configuration from the Output data table instead of via the console port.    If there's no references to the I/O or M1/M0 files for that slot, then the module is a Series A or it's just not using that feature.   You'll have to connect to it over RS-232 to get the specific configuration of the serial port, but there's a 90% chance it's just set up to behave like a DF1 Full Duplex to DH485 bridge.    The 1747-KE does not route comms through the backplane;  the RS-232 port and the DH485 port need to be physically cabled to something.    They were often used to connect dial-up modems to a DH485 network to allow remote connectivity to an SLC-5/03 based control system.   If all the devices were wired into a DH485 network, the KE would give you access to both the SLC and the PanelView without needing a local 1747-PIC connection. The user manual for the 1746-OA16 and it says 2 mA off-state leakage, and the 1769-OA16 user manual shows the same.   I'd say those modules are equivalent. I tend to prefer to migrate simple old PanelView Standard applications manually to Red Lion, but you can migrate to PV+ using those tools as well, once you upload the program (or use a memory card to copy it out of the terminal).
  9. What kind of HMI device are you using ? How does the HMI read the flowrate ? If the HMI reads from the MicroLogix 1400 data tables, that's fine.    We can figure out where the data is being scaled incorrectly by examining the MicroLogix 1400 program and the HMI program. If the HMI is reading directly from the Promag 50, or from some other instrument, we need to know that to figure out the difference between those signals.  
  10. You have asked a variety of questions about this project for the past several months, including correspondence directly with other Forum members. If you are taking it up again, please provide details. You have repeatedly claimed that your PLC "pulse count" does not match your HMI "pulse count" but you have not explained if they use different instruments, or if the HMI shows a value from inside the PLC.   Do not start posting a new question and expect Forum users to research your past to understand the history of the system you are analyzing.
  11. Selectable Timed Interrupt (STI)

    I cannot understand what you are trying to do;  you're forcing Inputs and Outputs off as well as fussing with the STI, and you're doing it all in the Emulator instead of using real I/O.   What is your purpose with this logic ?
  12. Selectable Timed Interrupt (STI)

    Many of the hardware-related features like discrete interrupts don't work in the Emulator;  the Knowledgebase goes into some depth: But the STI is supposed to work with the Emulator. I don't understand why you are enabling and disabling the STI in the same File 2.   It's a timed function, and is going to be disabled except between the last rung and the start of the next program scan.   When did you expect it to execute ?
  13. The MicroLogix operating system only automatically executes Ladder 2. All of your other Ladder routines must be called with a Jump to Subroutine (JSR) instruction from Ladder 2, or executed by a system interrupt.
  14. 1756-hsc/b problem

    Does the control room meter display get its signal from the same flowmeter output ? When you change over a PLC to a new model, most of the I/O and signals work in a similar way.   But they aren't always exactly the same, so you need to research signals like this one. I don't think it's fair to say "it's very strange" until you have examined the whole system and program.
  15. 1756-hsc/b problem

    Thanks for the screenshots ! Those appear to show that your PLC-5 code used a data block starting at N9:84 that was 44 Words long to configure the 1771-VHSC.    The screenshots of N84 show that all the values in that data block are zero, which suggests that the VHSC was configured for all defaults, which you've assessed to mean Counter Mode, No Store, Rollover = 0, Preset = 0, and Scaler  = 0. What kind of pulse signal does your flowmeter generate ?   What's the voltage, what's the pulse rate, and how long (in ms) are the pulses ?   I'd have to look up the default filters on the 1771 and 1756 modules to see if they're similar. How do you evaluate your flow;   do you count up a number of seconds then capture the Accumulated Count, then calculate the flow ? Could the logic that triggers that calculation be different between the two systems ? Is the ControlLogix sending this flowmeter data back to the PLC-5 for you to do that calculation (I see that there's some copying of the 32-bit value into ControlLogix tags that are equivalent to N8:70-71 and N8:72-73)  ? Is the deviation of the volume flow consistently above the old measurements, or consistently below, or is it always different ?