Specifications

Ethernet Loop Testing
Page
E-4
Receiptvalue = array [l..receiptSize] of Bit;
E.2.1 Data Interface
This' section describes the data communication functions available to
the user. These functions are the interface to the Loop Requester.
There is no data interface to the~oop Server.
The Loop Requester module provides three functions and one procedure
as an interface for user module loop testing services.
Functions:
LoopDirect
LoopAssisted LoopPoll
Procedure:
LoopAbor
t
E.2.1.1 LoopDirect
The LoopDirect function is used to determine if direct communication
with a remote station is possible.
function LoopDirect
(
remoteAddress: Addressvalue;
transmitBuffer: BufferValue;
var receiptNumber: Receiptvalue;
var receiveBuffer: BufferValue): LoopDirectStatus;
type LoopDirectStatus
= (accepted,wrongState);
With the following definitions:
remoteAddress
- the identification of the station with which
communication is to be checked. The address can be a multicast
address, in which case success is defined as a response from any
station in the multicast group. If no address is specified, the
loopback assistant gfloup multicast address is used.
transmitBuffer
- a buffer containing the data to be
looped.
receiptNumber
- the request identification used in LoopPoll or
LoopAbort to identify this request,
receiveBuffer
- an optional buffer to contain the looped back
data. If no buffer
is supplied (i.e. BufferMaximum = O), the
looped back data is not returned to the caller.
LoopDirectStatus
- the status of the request. One of:
' accepted - the loop will be attempted.