Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

208 Chapter8
Intrinsics Reference
FDEVICECONTROL
The exception to this occurs when parm1 is set to 1 to
specify a new terminal type or printer type file for use.
In this case, the length of the character array
containing the name of the file to be used is specified in
the length parameter.
controlcode 16-bit signed integer by value (required)
Specifies the code number of the operation to be
performed. This section of the manual assumes that
controlcode is 192 (device control directive). No
controlcode values other than 192 can be used for
asynchronous terminals. The permitted values for
controlcode and their associated functions are listed
in Table 8-7.
parm1 16-bit unsigned integer by value (required)
Specifies the control directive for the device file
specified in filenum. The permissible values and their
associated meanings are described later in the “Device
Control Directives” section.
parm2 16-bit unsigned integer by value (required)
When controlcode is 192, indicates whether the call
will read or write device control value. Use the
following values to indicate the desired access for the
call:
1 = Return current value in buffer
(Read)
2 = Set item to value in buffer
(Write)
3 = Return current value in buffer
(Read/Write) and set item to
value in buffer
Table 8-8 shows the type of access allowed for each
parm1 value.
fserrorcode 16-bit unsigned integer by reference
(required)
Returns a file system error code number if an error
occurs. If no error occurs, fserrorcode is set to zero.
Condition Codes
CCE Request granted.
CCG Not returned by this intrinsic.
CCL Request denied. An error occurred.