devNode supports two EPICS record types:
devNode interprets the following record fields:
INP/OUT - This must be of type INST_IO.
The expected format of the INP/OUT fields is "@node_name", where
node_name is the name of the variable created by a drvNodeInit call.
For example, a record having an INP field of "@COMMON", requires the variable COMMON defined before iocInit:
The device support for stringIn records does not overwrite the VAL field if the call to drvNodeRead() returns ERROR.