I/O Description: MTX-IoT [3-S-N-N] / MTX-IoT [4-S-N-N]

Description of I/O interfaces:

• DB15 expansion connection: 3 digital inputs (2 of them pulse counters), 2 digital outputs and 2 A/D conversors (0-50V in tension mode, 0-20mA in current mode)
• Serial interfaces: 1x RS232 (DB9), 1x RS232 (DB15) or 1x RS485 (configurable with switches)
• MTX-Tunnel software uses inputs/outputs the following way:

GPIO	LOCATION	PIN	I/O	FUNCTION	@MODBUS
GPIO1	DB15	4	Digital input	Wake up/pulse counter	1/13-14
GPIO2	DB15	11	Digital input	SMS alarm/pulse counter	2/15-16
GPIO3	DB15	9	Digital input	User/pulse counter	3/17-18
GPIO4	DB15	5	Digital output	User	4
GPIO5	DB15	12	Digital output	User	5
ADC1	DB15	15	Analog input	User	11
ADC2	DB15	13	Analog input	User	12
VExt	DB15	10	Output voltage	4V	—
GND	DB15	14	Ground	Ground	—

• The column “GPIO” indicates the virtual GPIO corresponding to the GSM module inside the modem
• The column “Location” indicates in which connector of the modem the I/O is located
• The column “Nº PIN” indicates in which pin of DB15 connector the I/O is located
• The column “I/O” indicates I/O type
• The column “Function” indicates if GPIO has a special task inside MTX-Tunnel. If neither “Wake up” nor “SMS alarm” are used, you can use the digital inputs GPIO20 and GPIO21 as user’s digital inputs. If the options ‘Wake up” and “SMS alarm” are used, MTX-Tunnel uses the inputs GPIO20 and GPIO21
• The parameters OUTPUT_xxx1 refer to PIN 5 of DB15 connector
• The parameters OUTPUT_xxx2 refer to PIN 12 of the connector DB15
• GPIO20 and GPIO21 are optoisolated inputs that can be activated by GND (PIN 14 of DB15 connector). GPIO7 is a digital input CMOS activated by VOUT (PIN 10) of DB15 connector

Jumpers configuration

The modem has serveral switches that allow several configurations:

• [SW1 off] + [SW2 on]: RS232 DB9 on, RS232 DB15 off, RS485 on
• [SW1 off] + [SW2 off]: RS232 DB9 on, RS232 DB15 on, RS485 off
• [SW7 off]: voltage analog input 1 (0-50V)
• [SW7 on]: current analog input 1 (0-20mA)
• [SW8 off]: voltage analog input 2 (0-50V)
• [SW8 on]: current analog input 2 (0-20mA)

PIN	SIGNAL	DIRECTION	LIMITS	DESCRIPTION
1	-RxB	I/O		RS485 B signal (see section Interface Description 5 (RS485 bus) for details)
2	+RxA	I/O		RS485 A signal (see section Interface Description 5 (RS485 bus) for details)
3	NC			Not connected
4	VIN	Input	7-50VDC	Positive power input
5	GND	Input		Negative power (ground)