Topside connections
The micromatch pin connections are used to connect to the display.
Expansion connections
| PIN | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| CONFIG | Reserved – don’t use | |||||||||
Communication connections
| PIN | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|
| CONFIG | VIN (11-32VDC) | GND | METER_TX (RS232) | METER_RX (RS232) | RS485A | RS485B | 0-5V OUT (analog) | GND |
12C connections
| PIN | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| CONFIG | Reserved – don’t use | |||
Underside connections
Gas concentration data is available on the RS232 and RS485 digital communication channels. The RS485 channel is 2-wire, the RS232 is 2-wire plus GND.
Data is also available as a 0-5V signal at the 0-5V and AGND terminals.
Note: Plug-in screw terminal connectors are supplied with the SM50.
Terminal connections
| PIN | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| CONFIG | 0-5V | AGND | TX | RX | A | B | NO | COM | NC | V+ | GND |
| DAC | RS232 | RS485 | RELAY | POWER | |||||||