ConnectPort X4H Serial Port
From Digi Developer
Contents |
Digi ConnectPort X4H Serial Port
Models
The CPX4H (or X4 NEMA) has one internal serial port with supports RS-232 and RS-485 2 or 4 wire. RS-422 can be connected as RS-485 4-wire as long as the remote device can handle the RS-485 compliant signal levels.
The serial port is via a 9-screw terminal block. The mating connector is a Phoenix Contact MC-1.5/9 xx-3.5 line.
Configuration and Wiring
The mode is set via software. Under the web interface, it is Configuration -> Serial Ports -> Multiple Electrical Interface (MEI) Serial Settings. Generally you should enable termination on all Digi RS-485 ports, because that also enables the critical line-bias. With termination off, the RS-485 float when no device transmits and this can cause lots of noise on the line.
For more information, see this Wiki page: RS485_DB9_on_Connect_Products
Pin Outs
Pin #1 is identified by a white paint dot in the overlay. (Do not be mislead by the larger copper test point near the wrong end of the connector - the pin #1 white dot is very close to the terminal block)
| Pin | RS-232 | RS-485 4-wire | RS-485 2-Wire |
|---|---|---|---|
| 1 | DCD = Input | CTS-- = Input | Not Used |
| 2 | RXD = Input | RXD+ = Input | DAT+ (often B) |
| 3 | TXD = Output | TXD+ = Output | Not Used |
| 4 | DTR = Output | RTS-- = Output | Not Used |
| 5 | GND, Signal | GND, Signal | GND, Signal |
| 6 | DSR = Input | RXD-- = Input | DAT-- (often A) |
| 7 | RTS = Output | RTS+ = Output | Not Used |
| 8 | CTS = Input | CTS+ = Input | Not Used |
| 9 | Not Used | TXD-- = Output | Not Used |
Note: "A" is often "-" and "B" is often "+". For historical reasons, some vendors reverse label "A" and "B", so it is a less predictable naming convention than +/- (which a few vendors also reverse label!) So make sure you try swapping the +/- (A/B) if you cannot communicate. EIA-422/485 compliant devices cannot be damaged by reverse wiring the +/- (A/B) signals.
