G120XA Drive Local Remote Speed Control Setup Guide
Configuring a drive for both local and remote operation is a common requirement in industrial automation. This article explains how to set up a G120XA drive to switch between local potentiometer speed control and remote PLC analog signal control, using digital inputs for start/stop and mode selection.
Understanding the Control Architecture
The G120XA drive supports flexible control configurations through its parameter set. In this setup, we use two distinct command data sets (CDS) to define local and remote behaviors. The local mode uses a potentiometer connected to analog input 0 (AI0) for speed reference and digital input 0 (DI0) for start/stop. The remote mode uses a PLC analog output (0-20 mA) connected to AI1 for speed reference, while still using DI0 for start/stop. A separate digital input (DI1) toggles between these two modes.
Important: Before changing parameters, ensure the drive is in a safe state and follow all safety procedures. Parameter P1900 should be set to 0 to disable automatic motor identification during this configuration.
Parameter Settings for Local/Remote Control
The following table summarizes the key parameters and their settings. These parameters define the command sources, speed references, and digital output functions.
| Parameter | Setting | Description |
|---|---|---|
| P1900 | 0 | Disable motor identification |
| P29652[0] | r722.0 | CDS0: DI0 as start/stop source (local) |
| P29652[1] | r722.0 | CDS1: DI0 as start/stop source (remote) |
| P756[0] | 0 | AI0: 0-10V input (potentiometer) |
| P756[1] | 2 | AI1: 0-20mA input (PLC) |
| P1000[0] | 2 | CDS0: Speed setpoint from AI0 |
| P1000[1] | 7 | CDS1: Speed setpoint from AI1 |
| P810 | r722.1 | DI1: CDS selection (local/remote switch) |
| P730 | r52.2 | DO0: Running feedback signal |
| P731 | r52.3 | DO1: Fault feedback signal |
| P840[0] | r29659.0 | CDS0: Enable start/stop from DI0 |
| P840[1] | r29659.0 | CDS1: Enable start/stop from DI0 |
Wiring and Hardware Setup
For the local mode, connect a 10kΩ potentiometer to the drive’s analog input 0 (AI0) and the 10V reference supply. The wiper of the potentiometer provides a 0-10V signal proportional to the desired speed. For remote mode, connect the PLC analog output (0-20mA) to AI1. Ensure proper shielding and grounding to minimize noise interference. Digital input DI0 should be wired to a maintained switch or pushbutton for start/stop control. DI1 is connected to a selector switch to choose between local and remote modes.
Tip: Use shielded twisted-pair cables for analog signals and keep them separate from power wiring to avoid electromagnetic interference.
How the Switching Logic Works
The drive uses two command data sets (CDS0 and CDS1) which are selected by the state of DI1 (P810 = r722.1). When DI1 is low (0), CDS0 is active, corresponding to local mode. When DI1 is high (1), CDS1 is active, corresponding to remote mode. The start/stop command in both modes comes from DI0, but the speed reference source changes: AI0 for local, AI1 for remote. This allows seamless transition between manual and automated control without rewiring.
Practical Considerations and Troubleshooting
Before commissioning, verify that the analog input scaling matches your application. For AI0 (0-10V), the default scaling is 0-50Hz or 0-60Hz depending on motor rated frequency. For AI1 (0-20mA), you may need to adjust parameters P757[1] to P760[1] to match the PLC output range. If the drive does not respond as expected, check the following:
- Ensure P1900 is set to 0 to avoid motor identification interfering with control.
- Confirm that the correct CDS is selected by monitoring parameter r0050 (actual CDS).
- Check the status of digital inputs via r0722 and analog input values via r0755[0] and r0755[1].
- Verify that the enable signals (P840) are correctly linked to the start/stop source.
Warning: Always test the configuration with the motor disconnected first to ensure correct logic and avoid unexpected motion.
Expanding the Application
This local/remote control scheme can be extended to other G120XA applications. For example, you could use additional digital inputs for jog functions or preset speeds. The drive’s flexible I/O and parameter structure allow for customized solutions in conveyor systems, pumps, fans, and other industrial machinery. By understanding the CDS mechanism, you can design control panels that meet specific operational requirements while maintaining safety and reliability.
For more advanced setups, consider using fieldbus communication (PROFINET, PROFIBUS) for remote control, which can replace analog signals with digital commands, offering higher precision and diagnostic capabilities.
