Triangulation Test; Introduction; Timeout Policy; Figure 192 Triangulation Test - Honeywell HPM Service

5.4

Triangulation Test

ATTENTION
This test requires a minimum of one NIM and one server (other UCN nodes). With only two
nodes, the NIM talks point-to-point. Three nodes are required for true triangulation.

Introduction

In the triangulation test, as illustrated in the following figure, only nodes that are configured in the test
are capable of token passing participate. For example, HPMs that have not been loaded, cannot pass
tokens and therefore do not participate. For those nodes that do participate, the test Master issues a
message to another node in the test and requests the message to be forwarded to a third node. The third
node in the test then sends a message back to the test Master, which verifies that the path has
successfully completed. While passing the message, the following communication paths are checked:
Master (NIM) to Slave 1, Slave 1 to Slave 2, and Slave 2 to back to the Master.
(3 ) Slav e 2 pas ses
mes sage t o MASTER
HPM
(Slav e 2)
HPM
(2 ) Slav e 1 pas ses m essage to Slav e 2

Timeout policy

Because a message may be lost or an error may occur, the Master has a reasonable timeout policy for
receiving the response back from Slave 2. The timeout policy assumes that each Slave in the test is
serving only one Master. This means that responses arriving late are considered errors. By examining
several paths together, it is usually possible to determine which nodes are experiencing communication
problems.
R688
December 2020

Figure 192 Triangulation Test

NIM
(Master)
(1 ) Mast er passes
m essage to Slav e 1
(Slav e 1)
UCN
HPM High-Performance Process Manager Service
Honeywell
HPM
HPM
16088
5 UCN Exerciser
5.4 Triangulation Test
393