Hey Mike,
I would check cabling of the signal wires and if they have a good connection.
I would check if there is the issue with the breakout board adapter which was reported here. It’s about the breakout board adapter not getting any or no proper connection to the pins of the Onefinity Controller because the screws/sockets of the DB-25 connector/breakout board adapter prevent that.
As Martin @MVall already suggested, some users also had success with switching the two signal wires around.
You can also experiment with altering communications speed. This sometimes can help if the line is noisy. But you got to have matching values on Onefinity Controller and VFD:
| Onefinity Controller baud |
VFD F164 |
|
|---|---|---|
| 4800 | 0 | |
| 9600 | 1 | |
| 19200 | 2 | |
| 38400 | 3 |