Pro 4
Pro 4, Pro 4

Diagnostics and Repair - Communications

Communications problems can result in loss of control of the ROV. Communications in the Pro 4 occurs at several levels.

The computer has to communicate with the control panel via the USB cable. First verify that the cable is connected. The computer must also recognize the control panel devices, specifically the RS-485 interface. The RS-485 device will only be recognized while the control panel is turned on. To check the status of the communications with the RS-485 device, the control panel must be turned on. The RS-485 interface can be confirmed by checking the Ports in Device Manager. To access device manager, open the Windows Control Panel, and in the Classic View, click on System. Next, click on the Hardware tab, and then the Device Manager button. Click on the plus sign (+) next to Ports and confirm that the SeaLevel RS-485 port is listed as one of the ports. If the RS-485 device is not listed, unplug the USB cable, wait a few seconds and plug it back in. If the RS-485 device is still not listed, power down the control panel and reboot the computer. If the RS-485 device is not listed after a shut down, restart and reboot, a problem with the USB cable, RS-485 device, or internal USB hub or controller is possible.

The control panel must communicate with the ROV through the tether. Communications occur via pins 7 and 8. verify the continuity of the tether to ensure all conductors are intact. The tether conductors are straight through - pin 1 to pin 1, pin 2 to pin 2, etc. You can also connect the ROV directly to the control panel without the tether to either rule out or confirm whether the tether is the problem.

Test Points

Test Procedure / Location Expected Result
Communications device present Verify "SeaLINK +485Isolated USB to RS-422/485 Converter (COMx)" is visible in Device Manager under "Ports" Device recognized and no warnings
Measure tether Ohms for continuity Tether pin 7 male to pin 7 female Continuity
Measure tether Ohms for continuity Tether pin 8 male pin 8 female Continuity
Test tether for a short Tether pin 7 male/female to any other pin No short
Test tether for a short Tether pin 8 male/female to any other pin No short
Measure control panel Ohms Control panel tether pin 7 female to control panel tether pin 8 female 120 kOhm +/-
Measure ROV Ohms ROV tether pin 7 male to ROV tether pin 8 male 120 Ohm +/-
Measure ROV Ohms ROV tether pin 7 male to ROV accessory port pin 7 female 120 Ohm +/-
Measure ROV Ohms ROV tether pin 8 male to ROV accessory port pin 8 female 120 Ohm +/-
Measure ROV Ohms for continuity ROV tether pin 7 male to ROV accessory port pin 8 female Continuity
Measure ROV Ohms for continuity ROV tether pin 8 male to ROV accessory port pin 7 female Continuity

Document Path: Pro 4 Maintenance Manual > Diagnostics > Communications