The SMC_Scrapers device
Status:
The SMC_Scrapers device is now ready in a first version and is under test.
980414 JSN
Contents:
Overview:
This device will control a SMC Series Stepping Motor Controller from Thermionics Northwest, inc. which is the scrapers presently used at ASTRID. The present device controls only the simple scrapers without encoder readback. The scrapers are therefore calibrated by running the scrapers completely out and assigning a reference value for that position. This reference value can be changed at any time, though a ConSys Client.
Device parameters:
For addressdefinition the device uses AddTypeId number 6 (Motor addressing) which uses a0 to determine which motor is addressed and a1 to give the parameter number.
Generel parameters (a0=0):
|
parameter |
Suggested |
Parameter name |
Data type |
Interpretation |
Comment |
|
0 |
reset |
Resets the controller |
Bit (control) |
Bit, checkbox |
Writing a one to this parameter will reset the controller. This should not be nessarary very often, and should properly be a restricted parameter. |
|
1 |
ok |
Overall status |
Bit (status) |
Bit, Concat. String (nr 522) |
A zero indicated all is OK, and a one that something is wrong. |
|
2 |
comm |
Communication status |
Bit (status) |
Bit, Concat. String (nr 522) |
A zero indicates that the communication is OK, and a one that the communication is not OK (i.e. probably the cable is not connected proper.) |
|
3 |
statStr |
Status String |
String |
String |
Gives the status of the device in words. |
Parameters for each motor (a0='motor nr'):
|
parameter |
Suggested SirName |
Parameter name |
Data type |
Interpretation |
Comment |
|
0 |
dac |
set position |
Float |
Bipolar Float (nr 140) |
Writing a value to this parameter initiates a movement of the scraper. |
|
1 |
adc |
Read back position |
Float (status) |
Bipolar Float (nr 140) |
Continuously read back of the position of the scraper (also during movement) |
|
2 |
refval |
Reference value |
Float (control) |
Bipolar Float (nr 140) |
Determines the value of the position at the reference point (i.e. when the scraper is completely out) |
|
3 |
refmov |
Reference movement |
Bit |
Bit, check box (nr 577) |
Initiates a calibration of the scraper. The scraper is moved completely in and the position is assigned the reference value. This procedure will give an uncertainty of up to one revolution (0.9 mm), because of the overrun of the thread. To achieve a better accuracy perform a manual calibration as described under setref. |
|
4 |
mov |
Moving |
Bit (status) |
Bit, Concat. String (nr 578) |
A one indicates that the scraper is moving, and a zero that the scraper is not moving. |
|
5 |
cal |
Calibration |
Bit |
Bit, Concat. String (nr 579) |
A one indicated that the scraper position is calibrated, and a zero indicates that the scraper is not calibrated. Note that is not possible to guarantee a calibration is valid, as the scraper can be moved manually and there is no way to detect this. |
|
6 |
setref |
Set reference position |
Bit (control) |
Pulse bit |
Sets the position to the reference position. Can be used after a manual fine trim of the reference position to get the best accuracy for the reference position. Fine trim is done by manually turning the scraper until the click. (Used a refmov first to get all the way in.) |
Device configuration:
The following parameters are stored in registry at the frontend computer on which the device is loaded:
- COM-Port: The serial port number.
- Baud-rate: The baud-rate used to communicated with the controller (the default is 1200 to avoid to high a dataload on the frontend computer).
- Number of motors: There can be up to 6 motors on a controller.
- For each motor the scraperMax movement.
Last Modified 29 March 2019