ZCOM Terminal Request Codes

Each request to or from a terminal has a request code indicating the type of operation. This code is in addition to the ZCOM message type. The request code is defined for all messages with message types ZCOM_MSTYPE_MSLT(1) and ZCOM_MSTYPE_RSLT(6) (or ZCOM_MSTYPE_MSRT(9) and ZCOM_MSTYPE_RSRT(14) for remote terminals). These are messages from terminals or responses from terminals.

The terminal request codes are as follows:

Request          Message     Description 
Code          Types 
 
0     ZCOM_MRCODE_UND     ----     For message types where the request 
                                   code is not defined, zero is returned 
                                   from the 'zread' call.
1     ZCOM_MRCODE_READ     1,9     Input message from terminal 
2     ZCOM_MRCODE_WRITE    6,14    Write completion from terminal 
3     ZCOM_MRCODE_CNTWR    6,14    Control write completion from terminal 
4     ZCOM_MRCODE_STDT     ----    Internal use only (status transfer) 
5     ZCOM_MRCODE_STATUS   6,14    Unsolicited terminal status change 
6     ZCOM_MRCODE_TERM     6,14    Set terminal parameters (response) 
7     ZCOM_MRCODE_ENB      6,14    Terminal enable (response) 
8     ZCOM_MRCODE_ENB      6,14    Terminal disable (response) 
9     ZCOM_MRCODE_ACT      6,14    Terminal activate (response) 
10    ZCOM_MRCODE_DEA      6,14    Terminal deactivate (response) 
11    ZCOM_MRQCODE_DEL     ----    Terminal delete(response)
14    ZCOM_MRQCODE_PORT    ----    'zport' call (returned status only)

The request code may be retrieved from any message which is read from a program ZLU via the MRQCODE field of the message header returned with zread and zpeek calls.