Chapter 1
Multi-Tech Systems, Inc. MultiModem iCell User Guide
11
GPIO (General Purpose Input/Output) Connector
The GPIO pins are configured using Universal IP (UIP) AT Commands. Refer to the Universal IP (UIP) AT Command
Reference Guide on your MultiModem CD. The following table explains the GPIO functions:
Pin Number
Description
GPIO 6-PinConnector
Pin 1
DIO 0
Pin 2
DIO 1
Pin 3
DIO 2 / ADC 0
Pin 4
DIO 3 / ADC 1
Pin 5
ADC 2
Pin 6
Gnd
The GPIO pins can be configured independent of each other.
●
Pin 1 Digital Input, 24 Volt tolerent.
●
Pin 2 Digital Input, 24 Volt tolerent.
●
Pin 3 can be configured as either Digital Input (5V tolerant TTL/CMOS levels) or Digital Output (3.3V High) or as an
ADC input (0 to 3.3V rail)
●
Pin 4 can be configured as either Digital Input (5V tolerant TTL/CMOS levels) or Digital Output (3.3V High) or as an
ADC input (0 to 3.3V rail)
●
Pin 5 is configured as an ADC input (0 to 3.3V rail)
●
Pin 6 is GND and must be connected to the ground of the attached device
GPIO DC Characteristics
Pins 1, 2
Input Voltage
Parameter
Min
Max
Units
Input Low-level Voltage
0.3
1.0
V
Input High-level Voltage
3.0
24
V
Pins 3, 4
Input Voltage
Parameter
Min
Max
Units
Input Low-level Voltage
-0.3
0.8
V
Input High-level Voltage
2.0
5.5
V
Pins 3, 4
Output Voltage
Parameter
Min
Max
Units
Output Low-level Voltage
0.0
0.4
V
Output High-level Voltage
2.9
3.3
V
Pins 3, 4
Output Current
Parameter
Min
Max
Units
Output Current
2
mA
Pins 1, 2 are digital input
only.
Pin 5 is an analog input
only.
Pins 1-5 contain ESD protection.
RS232 9-Pin Functions of the Female End Connector
External Power
Serial Cable
Female Connector
Signal
IN/OUT
Pin 1 CD
O
Pin 2 RX
O
Pin 3 TX
I
Pin 4 DTR
I
Pin 5 GND
--
Pin 6 DSR
O
Pin 7 RTS
I
Pin 8 CTS
O
Pin 9 RI
O
