First version
Rev 1.00
22 Sep 2016
Helios User Manual
18
Send command “8” (= open cover)
Check status register - 01 81 (01 = “open”; 81 = ack from cover command, ready to measure)
Send command “0” (= clear ack bits)
Check status register - 01 01 (01 = “open”; 01 = ready to measure)
Send command “10” (= close cover)
Check status register - 02 81 (02 = “closed”; 81 = ack from cover command, ready to measure)
Send command “0” (= clear ack bits)
Check status register - 02 01 (02 = “closed”; 01 = ready to measure)
2. To change measurement range:
Send command “2” (= set second energy scale, 1000J full scale)
Check status register - 01 41 (01 = “open”; 41 = ack from range command, ready to measure)
Send command “0” (= clear ack bits)
Check status register - 01 01 (01 = “open”; 01 = ready to measure)
3. Exposure Time Error status:
(NOTE: This status is given if the Helios exposure time circuit was triggered but not energy pulse was detected)
Check status register - 01 11 (01 = “open”; 11 = exposure time error; ready to measure)
Querying and Changing laser options:
(available from firmware v1.13, Sept 2020):
As of firmware version 1.13, the Helios supports multiple laser options. This allows users to select between more than
one built-in set of calibration factors, which are tailored to specific lasers or wavelength regions. For example, the
“NIR” laser option is suitable for near Infra-red wavelengths such as YAG 1064nm. In addition, there is another
option “B-G” for the blue – green laser region ~450-550nm. See the latest version of the datasheet for your model of
Helios for more details of available laser options.
There are several tools available to query and control the laser option.
Bytes 20-21 = number of supported laser options.
This value reports the number of available laser options; as of Sept
2020 there are 2 options (NIR and B-G).
Bytes 46-47 = active laser option index.
This value reports the active (presently chosen) laser option index, between 1
and N where N =
number of supported laser options.
Bytes 48-51 = Active laser name, characters 1..4
. These 4 bytes report the NAME of the active laser option as Ascii
characters. For example ‘NIR ’ would be 0x4E, 0x49, 0x52, 0x20 (the names are padded up to 4 characters with the
“space” character 0x20).
Commands 0xA1-0xA5 = set laser option 1-5
. These 5 commands are used to select one of the available laser options,
1 to 5. Attempting to select a laser option beyond the maximum defined ‘number of supported laser options’, will
cause an ‘Undefined command’ error bit in the Status Register (bit 13, see above). Successfully setting one of the laser
options will set the bit ‘Change in parameters – acknowledge’ in the status register (bit 14, see above).
Suggested method to scan available laser options:
In order to automate the selection of laser options, and to be ready in case new laser options are added to the Helios in
the future, it is recommended to scan the available laser options before selecting the correct laser, as follows:
1. Check the ‘number of supported laser options’ (= ‘N’)
2. Set the ‘active laser option index’ to 1 by sending command 0xA1 (set laser option 1)
3. Query the ‘active laser name’ of the first laser option and store in s/w
4. Repeat for laser option 2, 3, …. up to ‘N’
5. After scanning all the available options, choose the appropriate laser option required using commands 0xA1,0xA2
as required.