text: <s>[INST] PF70 EC / PF700 VC DriveStatus_AtSpeed bit Hi, I am using a PF700 VC drive and two PF70 EC drives. In my ControlLogix PLC, I am communicating with these drives over Ethernet/IP via 20-COMM-E modules. In my logic, I'd like to make use of the DriveStatus_AtSpeed bit in each of these drives. I am finding that this DriveStatus_AtSpeed bit is constantly turning on and off, even though my speed is well within the range of what I would consider At Speed. Can anyone tell me if there is a parameter in these drives that I can adjust to make this DriveStatus_AtSpeed bit a little more forgiving? Thanks in advance, Paul [/INST] Paul, If the drive is operating in Speed Control Mode (Velocity Regulator), the _At Speed bit should not turn on and off when the drive is running! The Speed Regulation Control Loop's ONLY duty is to keep the drive running at the commanded frequency! If the drive is operating in Torque Control Mode(Torque Regulator), the situation you describe is normal since the Torque Regulation feature of the VFD reduces/increases the operating frequency in order to maintain constant Commanded Torque. The third scenario (probably the one your application applies within) uses a combination of the two above mentioned modes. You could call it Speed Limited Adjustable Torque operation. The drive will automatically switch from speed to torque mode (or from torque to speed) based on the dynamics of the motor/load. If this is true, you could try using the _Active bit of the Logix5000 Status Word (instead of _AtSpeed bit-which would turn on/off when the drive is running in Torque Regulation) in order to monitor the operating status of the VFD. The _Active bit will become true when the drive is started up and will remain on until a Stop command has been issued. \\n </s>