The GPIO connector is Micro-Fit 3.0™ 2 x 7 position 3.0 mm pitch connector manufactured by Molex
Digital inputs have pull-down resistors. All general purpose I/O (GPIO) pins (i.e. all input and outputs) have transient protection.
The I/O port provides for the control of 4 external devices and for monitoring 4 external inputs.
GPIO Block Pin | Signal | Name |
1 | INPUT1 | Single Ended Input 1 |
2 | INPUT2 | Single Ended Input 2 |
3 | INPUT3 | Single Ended Input 3 |
4 | INPUT4 | Single Ended Input 4 |
5 | VCC | Power (Power supply output – fused) |
6 | RS485 | Negative |
7 | RS232 | RxD |
8 | DOUT1 | Output 1 |
9 | DOUT2 | Output 2 |
10 | DOUT3 | Output 3 |
11 | DOUT4 | Output 4 |
12 | GND | Common Ground for Power |
13 | RS485 | Positive |
14 | RS232 | TxD |
GPIO Output Connection
The 4 outputs are configured as “open drain” which means that they can be directly connected to energize external relays, lamps, or other DC devices.
Maximum supply voltage is 36 volts, with a maximum load current of 500mA.
Recommended wire gauge for use with the connector is 20-24 AWG. Note that the OUT GND connection is connected to the CTM-ONE’s supply ground.
GPIO Input Connection
The 4 inputs may be configured in the CTM-ONE for monitoring a digital DC voltage state or an analog DC voltage. All of the inputs are single ended.
For digital state monitoring, the minimum input voltage is 0 volts while the maximum is 36 volts.
The threshold detection voltage is 2.5 volts with 1 volt of hysteresis. Note that the IN GND connection is referenced to the CTM-ONE’s supply ground.
Analog input values will be sampled and can be reported at a maximum frequency of 10Hz.
Example of Digital Input wiring
For analog voltage monitoring the measurement range is 0 to +10 volts with 10mV resolution. The input can withstand up to 36 volts. Note that the IN GND connection is referenced to the CTM-ONE’s supply ground.
Example of Single Ended Analog Input Wiring
