atcsucStartFSSAcquisitionIp

Use Case: Start FSS Acquisition

Description: Start the APD measurements

Role(s)/Actor(s):
Primary: Operator, Maintenance
Secondary: FSS Strap

Package Assignment: Field Stabilization Subsystem.

Preconditions:

FSS Strap is ONLINE
FSS setup is available for the requested APD configuration

Basic Course:

Send command STRTOPN | STRTCLS to start the FSS Strap System
ATCS Sends FSS setup configuration to FSS Strap
Exception Course: Command failed
ATCS Sets APD Gate to 100%
Exception Course: Command failed
ATCS starts APD measurements
- Subflow: in Open Loop
- Subflow: in Close Loop
Interface: IfFss.Control.Start
Exception Course: Command failed
ATCS returns OK reply

Subflow: in Open Loop

ATCS starts APD Cycles with Open APD Loop
Postcondition:FSS Strap cycles performed in Open Loop (No M6 correction)

Subflow: in Close Loop

ATCS starts APD Cycles with Close APD Loop
Postcondition:FSS Strap cycles performed in Close Loop (with M6 corrections)

Exception Course: Command failed

ATCS returns ERROR reply
Postcondition: FSS Strap is idle

Postconditions:

FSS Strap active in Open or Close Loop
FSS Strap data available

Issues to be Determined or Resolved:

Issue 1: It must be defined how we know that the loop is stable: should we wait for a fixed time, or better should we use some diagnostic? What? Suggestions please….

Issue 2:The beahviour of the M6 as controlled by the APD system must be still analyzed on more details. This will most probably cause modifications in the FSS and M6 Use Cases and the introduction of new Use Cases for the M6.

ACTION MCO: Verify the following points regarding the interaction of the STRAP system with the M6:

the actual sequence to be used at FSS Acquisition STOP time is:
- Set the gate to 0
- Open the loop
or
- Open the loop
- Set the gate to 0
that M6 actually goes to the defined center position, using properly the defined offset from (0,0)
if the offset position is applyed:
- As soon as the SETUP with the new offset is sent
- When the loop is OPENED/CLOSED
This has an impact on the implementation of chopping, as will be discussed in the following sections.
what happens when the gate is set to 0 ?
- M6 stays in previous position (should be!)
- M6 goes to defined offset position
is it the same when the loop is open or closed?
what is the behavious when the loop is opened/closed?
Notes:
Last modified: Tue Jan 22 14:41:00 UTC 2002