Difference between revisions of "No data on serial ports"
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[[Category: AlphaCom Troubleshooting]] | [[Category: AlphaCom Troubleshooting]] | ||
Revision as of 11:52, 8 September 2017
On AMC-IP boards hardware version 8000/3 and earlier there is a possible problem with the RS-232 serial ports. In the AMC-IP hardware version 8000/4 this problem is resolved.
Description
The PCB version 8000/3 has a "auto shut-down" feature on the RS232 driver. The RS232 transceiver (MAX3221) will shut down if no valid transitions are detected on receiving and transmitting side. If the connected equipment only is connected, and not sending, the transceiver will shut down when more than 30 seconds pass without data traffic from AMC-IP. The transceiver will turn back on when valid transitions are detected, but this will take some time, and data will be lost. It is strongly recommended to do the hardware modification in order to ensure proper operation. The problem applies to both serial ports. In the latest AMC-IP hardware version, PCB 8000/4, this modification is implemented.
The hardware version is found at the rear side of the AMC-IP, in the top right corner.
Modification
Modification (PCB 8000/3 and earlier):
- Remove resistors R695 and R698
- Connect a strap from R695 to pin 16 on U604 ( Vcc 3,3V)
- Connect a strap from R698 to pin 16 on U605 ( Vcc 3,3V)