YASKAWA MP920 User Manual page 306

217IF RS-485 Panel-to-Panel Cable Connections
The following figure shows a 217IF RS-485 panel-to-panel cable connection example.
SRD S
+ -
120Ω
Fig. D.10 217IF RS-485 Panel-to-Panel Cable Connection Example
• Connecting Signal Lines
Use panel-to-panel cables to connect the incoming and outgoing SRD+ and SRD- signal
terminals on each control panel as shown in the above figure.
• Connecting Terminating Resistances
Mount terminating resistances at both ends of the transmission line.
• Connecting Shielded Ground Trunk Cables
Connect the shield of each panel-to-panel cable to shielded wire junction terminal S on
each control panel and ground it at one point only.
Using a ground wire of 8 mm
pole with a ground resistance of 100Ω or less.
SRD S SRD S
+ - + -
Panel-to-panel
cable
2
or greater, ground the shield to an independent ground
D-15
D.2 Indoor Panel-to-Panel Wiring
SRD S
+ -
E
120Ω
2
8 mm
Independent ground
pole: 100Ω or less
D