Fications - Johnson Controls Penn VFD68D Series Technical Bulletin

Appendix 4: VFD68Bxx and VFD68Cxx ModBus RTU RS485
Communications Bus Specifications
You must create a custom RS485 communication cable to connect the VFD68Bxx or VFD68Cxx to the head
end of a ModBus RTU network.
Figure 55: VFD68Bxx and VFD68Cxx Identification of RJ45 Receptacle
IMPORTANT: Do not connect pin 2 or pin 8 to a communication cable. Pin 2 and pin 8 of the RJ45
receptacle are connected to a power supply in the VFD68 drive. Connecting one or both of these pins to a
communication cable may damage the VFD68 drive.
Table 85: VFD68Bxx and VFD68Cxx RJ45 Pin Identifications for Communications Bus
Pin Number Name
1 SG
2 —
3 RDA
4 SDB
5 SDA
6 RDB
7 SG
8 —
Description
Earth (ground) (connected to terminal 5)
Power supply
VFD receive (+)
VFD send (-)
VFD receive (+)
VFD send (-)
Earth (ground) (connected to terminal 5)
Power supply
VFD68 Variable Frequency Drives
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