LDSS-2 Local Controller Software Description

Revision 1.0 28th February 1992 Graham Shaw

1. Introduction

This document describes the LDSS-2 local controller software.

2. Diagnostic Words

The following diagnostic words are available:

SIGN-ON Sends network address

NET101 Purpose unknown

M-LIST Display contents of monitor-mode list

S-LIST Purpose unknown

WHO Purpose unknown

TRANSPARENT Communicate directly with SMDM associated with mech on TOS

TT Shorthand for TRANSPARENT

.SLINKS Display status of SMDM serial link and of air pressure

#LINK Purpose unknown

LLL Shorthand for #LINK

KKK Purpose unknown

.TIMEOUTS Display number of comms timeouts since last reset

SEE Display present-status table for mechanism number on TOS

.MECHS Purpose unknown

#SLINK Purpose unknown

LOCAL Enter command as if it had been received over the ethernet

| (Pipe) Shorthand for local

Where these words require a mechanism number on top of stack, the following mnenomics may be used:

APW Aperure wheel (0)

SCC Shutter Control Card (5)

With the exception of .SLINKS, the above diagnostic commands behave in the same manner as existing RGO 4MS software. The behavior of TRANSPARENT is as for a standard SMDM.

3. Mechanism Summary

LDSS-2 has six mechanisms, as enumerated in the proceeding section. There are also six pseudo-mechanisms: INS, MON, HMS, ALL, RES and NET. These are not documented here, as they are as for existing RGO 4MS software.

3.1 APW (Aperture Wheel)

Commands:

APW101(n) Move wheel to position n (between 0 and 7)

APW102 Initialise mechanism

APW181 Reprogram SMDM

APW182 Initialise from arbitary position

APW183(n) Clamp wheel (n=0) or unclamp wheel (n=1)

(Note: APW102 is the normal initialisation command, but it only works if the wheel begins from a clamped position. APW182 can be used to initialise from any position, but should only be used while the telescope is at zenith. The APW100 command (Stop) is implemented, but should not be used as it could cause damage to the mechanism.)

Return values as for existing RGO software, but note:

Position Range 0..7, or 1 if in transit between two positions

Stepcount Range 0....31 999

Datum Sw. Bit-0 true if clamped, bit-1 true if unciamped

New mechanism error codes (hex):

13 Failed to clamp wheel

14 Failed to unclamp wheel

16 Failed due to wheel/door interlock

10 Failed due to wheel/air pressure interlock

Interlocks:

The wheels will not move unless the doors are both closed and locked. This interlock can be overridden using the manual control handset.

3.2 FLW (Filter Wheel)

Commands:

FLW101 (n) Move wheel to position n (between 0 and 7)

FLW102 Initialise mechanism

FLW181 Reprogram SMDM

FLW182 Initialise from arbitary position

FLW183(n) Clamp wheel (n=0) or unclamp wheel (n=1)

(Note: FLW102 is the normal initialisation command, but it only works if the wheel begins from a clamped position. FLW182 can be used to initialise from any position, but should only be used while the telescope is at zenith. The FLW100 command (Stop) is implemented, but should not be used as it could cause damage to the mechanism.)

Return values as for existing RGO software, but note:

Position Range 0..7, or 1 if in transit between two positions

Stepcount Range 0..31 999

Datum Sw. Bit-0 true d clamped, bit-1 true if unclamped

New mechanism error codes (hex):

13 Failed to clamp wheel

14 Failed to unclamp wheel

16 Failed due to wheel/door interlock

10 Failed due to wheel/air pressure interlock

Interlocks:

The wheels will not move unless the doors are both closed and locked. This interlock can be overridden using the manual control handset.

3.3 GRW (Grism Wheel)

Commands:

GRW101 (n) Move wheel to position n (between 0 and 5)

GRW102 Initialise mechanism

G RW181 Reprogram SMDM

GRW182 Initialise from arbitrary position

GRW183(n) Clamp wheel (n=0) or unclamp wheel (n=1)

(Note: GRW102 is the normal initialisation command, but it only works if the wheel begins from a clamped position. GRW182 can be used to initialise from any position, but should only be used while the telescope is at zenith. The GRW100 command (Stop) is implemented, but should not be used as it could cause damage to the mechanism.)

Return values as for existing RGO software, but note:

Position Range 0..5, or 1 if in transit between two positions

Stepcount Range 0..31 999

Datum Sw. Bit-0 true if clamped, bit-1 true if unclamped

New mechanism error codes (hex):

13 Failed to clamp wheel

14 Failed to unclamp wheel

16 Failed due to wheel/door interlock

10 Failed due to wheel/air pressure interlock

Interlocks:

The wheels will not move unless the doors are both closed and locked. This interlock can be overridden using the manual control handset.

3.4 FOC (Camera Focus)

Commands:

FOC100 Stop Mechanism

FOC101(n) Move focus to position n (between 0 and 767 microns)

FOC 102 Initialise mechanism

FOC181 Reprogram SMDM

Return values as for existing RGO software, but note:

Position Range 0..767 microns

Stepcount Range 0..5000

New mechanism error codes (hex):

1E Failed due to SLVC/Focus Interlock

Interlocks:

The focus will not move unless the position sensor is connected to the ADC board. This is to prevent the mechanism
from attempting to servo when there is no feedback.

3.5 DOR (Access Doors)

Commands:

DOR101 (n) Unlock door (n=0) or lock doors (n=1)

DOR102 Initialise mechanism

Return values:

Position Indicates current status of the two doors:

Bit 0 false = door 1 locked

Bit 1 false = door 1 closed

Bit 2 false = door 2 locked

Bit 3 false = door 2 closed

Datum Sw. Duplicate of Position field

New mechanism error codes (hex):

15 Failed due to shutter/door interlock

17 Door 1 failed to lock

1 8 Door 2 failed to lock

1 9 Door 1 cannot be locked as it is open

1A Door 2 cannot be locked as it is open

1B Door 1 failed to unlock

1C Door 2 failed to unlock

Interlocks:

The doors cannot be unlocked while the shutter is open.

3.6 SCC (Shutter Control Card)

Commands:

None

(Note: this mnemonic exists only to allow status information to be returned from the shutter control card to the 4MS system, it does not therefore have any valid commands associated with it.)

Return values:

Stepcount Contains latest status information read from shutter control card. See network interface documentation for full details.

Interlocks:

The IPCS and CCD controllers cannot open the shutter unless the doors are closed and locked. The failure of an operation as a result of this interlock can be detected by monitoring the SCC stepcount field.

Release Notes for LDSS-2 4MS Software Vl.2:

1) Correction to grism wheel status maintain task. Previously, it was possible for the wheel to appear to be in position 6, even though it only had positions 0....5. Fixed.

2) New command and abbreviations for existing commands:

INTERLOCK STATUS (Abbreviation ILS)

(Display the status of the sensors likely to cause an interlock, together with the two hardware interlock-overrides (the door/shutter interlock and the door/wheel interlock) and the two software interlock overrides (the air pressure interlock and the focus/SLVC interlock).

AIR_ILOCK_VRIDE_ENABLE (Abbreviation E_AIR)

(Enable interlock between wheel mechanisms and air pressure switch.)

AIR_ILOCK_VRIDE_DISABLE (Abbreviation D_AIR)

(Disable interlock between wheel mechanisms and air pressure switch.)

FOC_ILOCK_VRIDE_ENABLE (Abbreviation E_FOC)

(Enable interlock between SLVC/ADC and focus mechanism).

FOC_ILOCK_VRIDE_DISABLE (Abbreviation D_FOC)

(Disable interlock between SLVC/ADC and focus mechanism).