Five LEDs are on the front of the RS-485 option module.
Figure 1. LEDs on RS-485 Option Module
|
Callout |
Description |
|---|---|
|
1 |
Upper COMn (for example, COM3) TX (Transmit) and RX (Receive) |
|
2 |
Lower COMn + 1 (for example, COM4) TX (Transmit) and RX (Receive) |
|
3 |
PWR - green, remains lit while controller is powered |
The LED pair RX and TX operate as follows:
- TX (yellow) — Transmit, flashes when the controller is sending data to a device connected on the RS-485 trunk.
- RX (green) — Receive, flashes when the controller is receiving data from a device on the RS-485 trunk.
LEDs are also visible when the front access door is opened.
Note: No additional features are behind the front access door of an RS-485 option module.