
First version
Rev 1.00
22 Sep 2016
Helios User Manual
21
negative, in which case it will be displayed as 2s-compliment, for example FF FF FF 27, Hex value 0xFFFFFF27,
decimal -217 mW)
00 1E - temperature of Helios. Hex value 0x001E, decimal 30 degrees C
00 01 - current energy scale is index 0x0001 (10kJ scale) - other scales are 2 (1kJ scale) and 3 (100J scale)
00 00 27 10 - max energy in current scale (J). Hex value 0x2710, decimal 10000 (J) or 10kJ
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 - spare bytes
Analysis of Example Data, LITTLE Endian:
This example shows how the same data as above will look with Little Endian format, for example when using
EtherNet/IP.
In this example, the data was obtained when the Helios was first powered up, before any measurements are taken.
8E 00 00 00 - header from EtherNet/IP
02 11 80 96 98 00 10 27 00 00 10 27 64 00 E0 2E 64 00 3C 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 81 00 00
00 1E 00 01 00 10 27 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
The data can be analyzed by splitting it up into groups as defined above, Constants and Measurement Results.
There are 66 bytes returned from the Helios. The first 4 bytes are a header (8E 00 00 00) generated by the system, and
are not part of the data from the Helios.
8E 00 00 00 - Header
02 11 - Status register bit map. In Binary: (lower byte, bits 7..0) 0000-0010, (top byte, bits 15..8) 0001-0001.
Starting from right-most bit (=bit 0):
Bit
Value
Notes
0
0
Cover is NOT open
1
1
Cover IS closed
2
0
Cover NOT in motion
3
0
NOT cover timeout error
4
0
NO cover other error
5
0
Spare
6
0
Spare
7
0
Spare
8
1
Sensor IS ready to measure laser
9
0
Measurement NOT in progress
10
0
Measurement NOT complete
11
0
Sensor NOT too hot
12
1
IS exposure time error
13
0
NO undefined command
14
0
NO ACK for Energy Scales command
15
0
NO ACK for cover command
Other Examples of Status Register values:
Status register = 01 01 (01 = “open”; 01 = ready to measure)
Status register = 01 81 (01 = “open”; 81 = ack from cover command, ready to measure)
Status register = 02 01 (02 = “closed”; 01 = ready to measure)
Status register = 02 11 (02 = “closed”; 11 = exposure time error; ready to measure)
Status register = 02 81 (02 = “closed”; 81 = ack from cover command, ready to measure)
80 96 98 00 - max energy that can be measured (mJ). Bytes are ordered most significant at the right, so true hex value
= 0x00989680, or decimal 10000000 (mJ) or 10000J or 10kJ
NOTE: This value is constant and can be used as a “signature” to locate the exact position of all the other bytes.
10 27 00 00 - min energy (mJ). Same order as above, hex value 0x00002710, decimal 10000 (mJ) or 10 J
10 27 - max exposure time (ms). Hex value 0x2710, decimal 10000 (ms) or 10 seconds