Troubleshoot Master Arm power and comms issues.
The Reach Robotics Master Arm is powered through a USB cable, and requires a minimum of 4.6 VDC to function properly. Most reasons why a Master Arm won't power on or communicate are to do with insufficient voltage.
Incorrect port
It sounds obvious, but it's always worth checking that you have selected the correct port in Reach Control for your Master Arm. You can double check which COM port the Master Arm is connected to by checking which ones are available in the Method dropdown in your Port configuration. Physically disconnect the Master Arm USB cable from the computer and check again to see which port has disappeared. Plug the cable back in and select the port that reappears.
Both COM4 and COM5 are available:
Only COM5 port is available now, so COM4 must be the correct port:
USB port not providing enough power
USB ports on computers and extenders can vary wildly in the amount of power they can provide. Most often, using an external USB hub to connect to the Master Arm is the cause of power or comms issues. Try to always plug the Master Arm directly into a USB port on your computer that you know to be powered with sufficient voltage, and avoid introducing external USB hubs unless they are sufficiently powered.
Cable gauge
If your Master Arm was released prior to August 2022, or has a serial number lower than SN7032, it's likely that it was sent with a 4.5mm gauge USB cable. In May 2023, a Technical Notice TN065 was released to customers stating that this cable can occasionally provide insufficient voltage to the Master Arm if the USB port doesn’t provide enough power. When the supply voltage drops below the functional threshold (4.6 VDC), the Master Arm will restart.
This restart state causes the button lights on the Master Arm to indicate that the controller is paused (flashing blue), despite still sending position demands to Reach Control.
Because the Master Arm appears “Paused” while still sending positions demands in response to movement of the controller, users may find that their slave arms move unexpectedly in response to those position demands. This risks damage to the controlled arm, the vehicle its mounted on, and any other equipment or people in the area.
If you find that your cable has a 4.5mm diameter, or has the product code E101344 printed on it, please contact Support for a new cable under warranty. We will send out a 5.4mm cable (product code E469596) to replace it.
Loose connector
Rarely, the connector on the base of the Master Base can become loose and cause intermittent comms problems. Check the connectors for any movement within the housing, and contact Support if you find any.