Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 336)

III. COMMAND REFERENCES - 15. Command References 15B. Driver488/SUB, W31, W95, & WNT
Personal488 User’s Manual, Rev. 3.0 III-321
EXAMPLE term.EOI = TRUE;
term.nChar = 1;
term.EightBits = TRUE;
term.termChar[0] = ‘\r’;
bytecount=EnterX(timer,data,1024,0,&term,1,&stat);
The EnterX command reads data from the I/O adapter. If an external device is specified, then
Driver488 is addressed to Listen, and that device is addressed to Talk. If an interface is specified, then
Driver488 must already be configured to receive data and the external device must be configured to
Talk, either as a result of an immediately preceding
EnterX command or as a result of one of the Send
commands. EnterX terminates reception on either the specified count of bytes transferred, or the
specified or default terminator being detected. Terminator characters, if any, are stripped from the
received data before the
EnterX command returns to the calling application.
The forceAddr flag is used to specify whether the addressing control bytes are to be issued for each
EnterX command. If the device handle refers to an I/O adapter, then forceAddr has no effect and
command bytes are not sent. For an external device, if forceAddr is TRUE then Driver488 always
sends the UNL , MLA , and TAG command bytes. If forceAddr is FALSE , then Driver488 compares the
current device with the previous device that used that interface adapter board for an EnterX command.
If they are the same, then no command bytes are sent. If they are different, then EnterX acts as if the
forceAddr flag were TRUE and sends the command bytes. The forceAddr flag is usually set TRUE
for the first transfer of data from a device, and then set FALSE for additional transfers from the same
block of data from that device.
Additional Enter Functions
Driver488 provides additional Enter routines that are short form versions of the EnterX function.
The additional Enter functions are: Enter , EnterN , EnterMore , and EnterNMore . These functions
are discussed in detail below:
Enter
SYNTAX long pascal Enter(DevHandleT devHandle, char *data)
REMARKS Enter is equivalent to the following call to EnterX :
EnterX(devHandle,data,sizeof(data),1,0L,0,0L);
The Enter function passes the device handle and a pointer to the data buffer to the EnterX function.
It determines the size of the data buffer provided by the user and passes that value as the count
parameter. It specifies forceAddr is TRUE , causing Driver488 to re-address the device. The default
terminators are chosen by specifying a 0 as the term parameter. Asynchronous transfer is turned off by
sending 0 for the async parameter, and the completion status value is ignored by sending 0 for the
compStat parameter.
EnterN
SYNTAX long pascal EnterN(DevHandleT devHandle,char *data,int count)
REMARKS EnterN is equivalent to the following call to EnterX :
EnterX(devHandle,data,count,1,0L,0,0L);
The EnterN function passes the device handle, the pointer to the data buffer, and the size of the data
buffer to the EnterX function. It specifies forceAddr is TRUE , causing Driver488 to re-address the
device. The default terminators are chosen by specifying a 0 pointer as the term parameter.
Asynchronous transfer is turned off by sending 0 for the async parameter, and the completion status
value is ignored by sending 0 for the compStat parameter.
EnterMore
SYNTAX long pascal EnterMore(DevHandleT devHandle,char *data)
REMARKS EnterMore is equivalent to the following call to EnterX :
EnterX(devHandle,data,sizeof(data),0,0L,0,0L);