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Raveon Technologies Corp.
features. Here is a wiring diagram for an RS232 DB9 connector to be wired to the
GPIO connector.
Or contact Raveon to have the device pre-configured when it is purchased.
SCADA and Telemetry Use
The GPIO is an ideal interface for wireless SCADA and Telemetry systems. It can
operate as a Remote Terminal Unit (RTU) which saves cost in your system. The Tech
Series radio modems support MODBUS RTU communication messages, so Telemetry
systems can utilize MODBUS messages to read and manage the GPIOs. See
application note AN234 for details on how MODBUS is incorporated into these Tech
Series modems. AN230 has detailed information about the MODBUS communication
protocol.
Configuring
The radio will auto-detect the GPIO board and set all necessary parameters to enable
it. By default, the IO pins are set to digital inputs.
Summary of Input and Output functions.
IO pins 3, 4, and 5 can be configured with built-in commands to be either digital inputs,
digital outputs, analog inputs, switched DC power output, open-drain outputs.
Digital Input Specifications:
Low-level input voltage:
Less than 0.5V
High-level input voltage:
Greater than 2.2V
Input resistance:
5K-10K pull-down resistance.
Digital Output Specifications:
Low-level Output voltage:
Less than 0.5V
High Level Output Voltage:
3.0 - 3.3V
Output resistance:
250 ohms
Open Drain Output Specifications:
Low-level Output voltage, on:
0V to 0.5V drawing less than 2.1A.
Open drain off leakage resistance
500uA, 0-5V, < 1mA 5-20V.
High Level Output Voltage, off:
0 - 20V
Output resistance, on:
<250 milliohms to ground
Switched DC power output: (IO1 and IO2) IO0 does not have this capability.
Output voltage, on:
Same as DC input, 90%-100%.
Maximum Output Current
2.0 amps
On state internal resistance
100-250mOhms.
Maximum reverse input voltage when off
DC input + 150mV
Off output off leakage resistance
5-200uA
High Level Output Voltage, off:
Same limit as RF board within the M21 enclosure.
Output resistance, on:
<25 0 milliohms to
ground
Analog Input Specifications:
Low-level input voltage:
0V
High-level input voltage:
Vin -1.0V. Vin is the voltage powering the Tech Series product.
Input resistance:
220K.
