text: <s>[INST] Usage of Drive Logic Command Bits over comm link? Hi, I am going to be using a PowerFlex 70 Enhanced Control drive for the first time. I ordered this with a 20-COMM-E Ethernet/IP to DPI Comm Adaptor. I will be using a ControlLogix PLC with a 1756-ENBT Ethernet/IP module. I'd like this CLX PLC to be completely in control of the drive - I want the CLX to issue all start / stop commands and to send the speed reference (setpoint) over Ethernet/IP. I also want the CLX PLC to be able to read the actual speed over Ethernet/IP. I am looking at the 20-COMM-E Ethernet/IP Adapter User Manual. Chapter 5 Using the I/O (page 5-11 figure 5-3 to be exact) shows an example ladder logic program that uses the Add-On Profile for to manipulate the drive logic command bits (Start / Stop / etc) in the drive. What I don't see here is an explanation of the proper usage of these bits. For example, I am guessing that Start/Stop logic would work like this: In order for the drive to be able to run, you have to keep the _Stop bit energized at all times. When the _Stop bit is energized, momentarily energizing the _Start bit will start the drive. While the drive is running, momentarily de-energizing the _Stop bit will stop the drive. ...I think this is probably how these bits work, but can anyone tell me if there is anything I should read that explains the proper usage of not only the _Start and _Stop bits, but also the less obvious logic command bits such as _LocalContrl, _SpeedRefID0, _SpeedRefID1, _SpeedRefID2, _MOPInc, _MOPDec. Do these bits function exactly as if you had configured a physical digital input (Digital Input 1-6) for the corresponding function of the bit? Any help will be greatly appreciated. Thanks in advance,Paul [/INST] Hi Paul, your assumptions aren't correct... :smileysurprised: The following is reguarding the Stop bit (bit 0) inside the Logic/Command word: A “0 = Not Stop” condition (logic 0) must first be present before a “1 = Start” condition on bit 1 will start the drive.The Start command acts as a momentary Start command. A “1” will start the drive, but returning to “0” will not stop the drive.In order to Stop the drive you'll need a logic 1 inside bit 0 of Logic/Command word. I suggest to review App.D of the Adapter User Manual to understand the Logic/Command word bits and how operate them; the same for the Status word. Feel free to post again if something still unclear. - fuzzy logic \\n </s>