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Digital Outputs

Each of 24 USB-I/O adapter GPIO pins can be configured as a digital output. Digital outputs can take on two different values: 0 and 1.

Output values can be set with GPIO_SET_OUT_VAL command.

[Warning] Warning

GPIO_SET_OUT_VAL command does not configure the pin as a digital output.

If a pin is in digital output mode, GPIO_SET_OUT_VAL command changes its output value immediately. If a pin is not in digital output mode, the command saves the output value in internal memory (in output data latches of every pin). The changes will be applied when the pin is configured as a digital output.

Use GPIO_SET_CFG command to switch the pin to digital output mode.

We recommend to set the output value before switching the pin to digital output mode. In this case you can be sure that the configured pin immediately starts to output the correct value.

Use GPIO_GET_OUT_VAL command to retrieve output values, stored in output data latches of every of 24 pins. If a pin is not configured as digital output, the value on the pin may differ from the value in its output data latch. Use GPIO_GET_VAL command to retrieve current output values on the I/O pins.

Digital Outputs Electrical Characteristics

Digital outputs of GPIO-24 adapter are CMOS compatible. The output voltage level depends on JP3 jumper. The digital outputs DC characteristics are specified in the following table:

Characteristic Min Max Units Condition
Digital output low voltage - 0.6 V I = 8.5 mA, -40°C to +85°C
Digital output high voltage (JP3 open) 4.3 - V I = -3.0 mA, -40°C to +85°C
Digital output high voltage (JP3 close) 2.6 - V I = -3.0 mA, -40°C to +85°C
Capacitive loading specs on digital outputs - 50 pF