Good Day,
This implementation of RS485 appears to be unique in that +VCC / GND is required. Furthermore, when measuring +VCC 5v (pin6) to GND (pin 2) with a DMM this voltage is not as I expected, it is fluctuating. It appears to modulate between TTL HI and TTL Low.
I would expect this to be a static value.
Please further define the REC RS485 implementation as I am experiencing a unique issue with a large Master-Slave (5) install.
With Gratitude