Author: Wallace Krebs
Category: Digital I/O

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An error can occur in the first SeaMAX I/O function call if a SeaMAX function call that is necessary to set up the communication with the I/O device is either missing earlier in the code or it did not complete successfully.

If the first I/O function call causes an error, verify either SM_Open() or SM_OpenSecure() is called earlier and that this earlier call is passed the same handle as the I/O function call receives. Verify this SM_Open() or SM_OpenSecure() call succeeds by checking its return value. Some other functions that may need called in order to set up the communication with the I/O device are shown below. These particular functions will not return an error if the parameters passed to them are different from the actual communication parameters in use by the I/O device. To verify they are being passed the parameters actually used by the I/O device, test the parameters from MaxSSD to see if they allow access to the I/O device.

SM_SelectDevice()
SM_ConfigureSerialConnection()
SM_ConfigureSerialTimeouts()

An error in the first call to an I/O function can also occur for the reasons common to all the I/O calls.  For instance the I/O function received an invalid parameter, or there is a hardware connectivity problem with the I/O device.