The Engineering Terminal

The Engineering terminal is a direct serial link to the 4MS, it allows access to the FORTH code used to control the instrument, however it is highly recommended that this is not attempted as a full knowledge of the software would be required to ensure no further problems are created.

A Help facility has been provided so that direct use of the FORTH code is not required, the facility displays information for all instrument mechanisms and is updated dynamically if the data changes, it also allows network commands to be input at the terminal, can give a direct command input to the Limpits, known as transparent mode and can be used to control power to the Limpits.

This is an example snapshot of the HELP display.

PFIP & ADC DYNAMIC HELP DISPLAY SOFTWARE VERSION 1.02

Mechanism : AFS LIMPIT : PFIP Mains : ON 24V: ON

Min target: 0 Max target: 1000 Steps between limits:10000

Serial link: 1 Channel nos: 2 Multiplexer nos : 3

Direct encoder reading : 10000 Operations : 0

Target 0 Position 1000

Enc.offset/detent/temp. 0 Barcode 0

Command error 0 Mechanism error 0

Network - Comms Rx Buffer

Tx Buffer

ADC - Comms: None Axis: 0 :None Axis 1: None

Transparent mode: OFF Tx last : Rx last

PFIP - Comms: None Axis 0: None Axis 1: None Barcode: None

Drive 1: None Drive2: None Drive 3:None Drive 4: None

Transparent mode OFF Tx last : Rx last :

N or I -Enter network message, P -Limit power, T -Transparent mode, m -Message

O-AFS, 1-AFW, 2-APX, 3-APY, 4-DOR, 5-HUM, 6-MFW, 7-SHS, 8-PFM, 9-ADI, A-ADO V,D, Q -QUIT

To start the Help display type HELP at the FORTH prompt, this display can be left running at all times.

The display is split into 4 areas of information.

PFIP & ADC DYNAMIC HELP DISPLAY SOFTWARE VERSION 1.02

This area shows the title and the running 4MS software version.

Mechanism: AFS LIMPIT : PFIP Mains : ON 24V: ON Min target: 0 Max target: 1000 Steps between limits: 10000

Serial link: 1 Channel nos: 2 Multiplexer nos : 3

Direct encoder reading : 10000 Operations : 0

Target: : 0 Position: 1000

Enc.offset/detent/temp.: 0 Barcode: 0

Command error: 0 Mechanism error: 0

Shown here is the mechanism selected for display, in this case AFS, and the information associated to that mechanism. The Limpit that the mechanism uses is displayed and the current state of the mains and 24V supply for that Limpit. The minimum and maximum target values in real units accepted for network move commands. The number of stepper motor steps between the limits of mechanism movement.

The Limpit Serial link number, Channel number and Multiplexer number used if relevant. The last encoder reading in A to D units if relevant.

The mechanism operations field.

The current mechanism Target value in real units.

The current mechanism Position in real units.

The encode offset at datum, detent position or temperature depending on the mechanism. The Barcode value if relevant.

Any command errors

Any mechanism error.

Network - Comms Rx Buffer

Tx Buffer

ADC - Comms: None Axis 0: None Axis 1: None

Transparent mode: OFF Tx last : Rx last:

PFIP - Comms: None Axis 0: None Axis 1: None Barcode: None

Drive 1: None Drive 2: None Drive 3: None Drive 4: None

Transparent mode OFF Tx last : Rx last

This area shows information on the communication lines. The Network communication receive and transmit buffers are shown, the last messages received and transmitted will be shown here. The allocation of the serial link the axis and the drives to a mechanism is shown, when the serial link is used for a mechanism or a Limpit axis or drive then the mechanism mnemonic is shown, as each of these can only be used for one mechanism at any one time.

Also shown is the status of Transparent mode to the Limpits, if Transparent mode is ON then this will be indicated, the last Transmitted and received commands are also shown.

N or I -Enter network message, P -Limit power, T -Transparent mode, M -Message

O-AFS, 1-AFW, 2-APX, 3-APY, 4-DOR, 5-HUM, 6-MFW, 7-SHS, 8-PFM, 9-ADI, A-ADO V,D, Q -QUIT

This area shows the key commands accepted and also includes the space used for command input. As shown pressing keys 0 through A selects the mechanism for which information is displayed. Pressing N allows a network command to be input at the engineering terminal, the section on Network messages discusses this.

Pressing key P allows control of the Limpit mains and the 24V to the drive cards, the section on Limpit power discusses this. T and M is used for Transparent mode discussed below in the Transparent mode section includes the commands required to control each mechanism, the commands accepted by the Limpits are shown in the Limpit Command List section.

V displays the Health Monitor Status display discussed in Part 4. D redraws the display and Q quits the Help utility.

Network messages

Pressing N in the Help Utility allows a message to be entered which will be treated by the 4MS software as if it arrived on the network, it allows a mechanism move or datum command to be used, however because no actual network connection is used, status requests cannot be used.

Using this facility the system can be tested without the use of the VAX or network. Valid network commands for each mechanism is shown in the mechanism information section in Part I and listed below.

ADI101(pos) Move ADI to pos, where pos equals -900 to +900 in 0.1 degree increments.

ADI102 Move ADI to datum position.

ADI100 Stop ADI movement.

ADO101(pos) Move ADO to pos, where pos equals -900 to +900 in 0.1 degree increments.

AD0102 Move ADO to datum position.

ADO100 Stop ADO movement.

AFS101(pos) Move AFS to pos, where pos equals 0 to 14100 urn in 10um increments.

AFS102 Move AFS to datum position.

AFS100 Stop AFS movement.

AFW101(pos) Move AFW to pos, where pos equals 1 to 6 filter positions.

AFW102 Move AFW to datum position 1.

AFW100 Stop AFW movement.

APX101(pos) Move APX to pos, where pos equals 0 to 110000 urn in 10um increments.

APX102 Move APX to datum position.

APX100 Stop APX movement.

APY101(pos) Move APY to pos, where pos equals 0 to 20000 urn in 10um increments.

APY102 Move APY to datum position.

APY100 Stop APY movement.

MFW101(pos) Move MFW to pos, where pos equals I to 7 filter positions, or -1 to -7 for filter positions I to 7 with detent left disengaged.

MFW102 Move MFW to datum position 1.

MFW100 Stop MFW movement.

Limpit power

Mains power for the Limpits and 24V drive card power for the Limpits are controlled using relays in the 4MS, these relays can also be controlled from
the Help Utility by pressing P and following the prompts to control the supply required. The 24v supply can be powered off then on to reset the drive cards if a problem is suspected. The mains is removed to reset the Limpits, allow a few seconds to pass before re-applying power then allow a further 40 seconds for the Limpit to complete its initialisation sequence.

Transparent mode

Transparent mode allows you to communicate directly with the Limpits from the engineering terminal in the control room, this gives direct control of
the mechanism stepper motors. Transparent mode is enabled from the help display by typing T, the user if then prompted for the Limpit to connect to, once connected the 4MS is not able to communicate

The following pages list the transparent commands required to control each mechanism, each mechanism is on at least a single page, all the commands
required to control each mechanism directly is shown. It is therefore important to use the official copy of this document kept in the WHT control room, as any amendments will be included in this document, if you do make any findings that you consider may be of value, please included them in the space provided for future reference, please include extra pages if necessary.

Following the mechanism listing is a full list of Limpit commands that can be used in transparent mode or when connected directly to the Limpit controller, some understanding of the Limpit is required to use these correctly, a brief description of the Limpits is included in the system overview section, and more detailed information is included in the Limpit document.