PTOP Common Parameters

Several parameters are common to more than one PTOP call. These common parameters are described in detail in the following paragraphs. Parameters that are unique to a specific call are described within the parameter description area of that call.

pcb

PTOP control block. A 4word array of any type. The contents

(input/output)

of the pcb parameter serve as a control block for the data link.

 

The pcb array resides within the calling program and must not

 

be modified.

err

Error code. Produces an error code if an error condition is

(output)

encountered during execution of a PTOP call. Must be defined

 

as a 16bit integer. If a slave program responds with a REJCT

 

during execution, a •1" is returned in err. If the slave program

 

responds with an ACEPT, the value •0" will be returned. Any

 

other value returned in this parameter represents an error in

 

the handling of the message.

tag

Tag field. A 20word array of any type. You can define

(input/output)

information to be exchanged between the master and slave

 

programs within the tag field. This parameter is passed from a

 

master program via a POPEN, PREAD, PWRIT, or PCONT call. A

 

slave program obtains the tag via a call to GET. A slave

 

program may then pass tag data back to the GET. A slave

 

program may then pass tag data back to the master program

 

via an ACEPT or REJCT call.

Master PTOP Calls

POPEN

APOPEN call directed to a remote node causes the named slave PTOP program at that node to be scheduled.

HP 1000 to HP 1000 Calling Sequence

For PTOP communications between HP 1000 nodes, you must call POPEN within a master program to initiate the communication link with a slave program.

POPEN(pcb,err,name,node,tag[,clon])

pcb

PTOP control block.

err

16-bit integer. Error return.

name

Slave program name. An array of up to 14 words containing the

 

ASCIIcoded slave program name and terminated by a blank or

 

nonASCII character.

node

16-bit integer. The Router/1000 node address of the

 

node where the slave program resides and where it is to be

 

scheduled for execution. A value of 1 indicates the local node.

tag

Tag field. A 20word array.

(input/output)

 

clon

Slave cloning parameter. Ignored when the slave is running in

 

an RTEA system. (Can be used to clone a slave program if the

 

slave resides on an RTE6/VM node with Session Monitor.

 

Refer to the DS/1000IV User's Manual for more information

 

on the use of this parameter.)

ProgramtoProgram Communication (PTOP) 121