Bristol 621 - Page 31

Model 621 User’s Manual APPLICATION PROGRAMMING INTERFACE (API)
Bristol Instruments, Inc. 31
Detailed examples
Note that byte offset and byte value fields are represented in hexadecimal values.
Request Wavelength (Read Back Lambda 1): Direction: APC  DSPB
Byte
Offset
Byte Name
Byte
value(s)
Byte Description
00
Start Token
7E
Generic message start identifier
01
Message ID
45
Unique message identifier
02
Sequence Number
01 – FF
Sequential message identifier
3-4
Checksum
0000 – FFFF
Checksum (2 bytes)
5-6
Payload Length
0000
Data length (2 bytes)
7-8
Pad
xxxx
Pad to word boundary (2 bytes)
Response example: actual bytes sent and bytes received from wavelength meter
using message 0x45, Read Back Lambda 1 (response wavelength = 0):
WRITE Length 9 bytes: 7E 45 06 40 07 00 00 05 01
READ Length 17 bytes: 7E 6B 35 63 B5 08 00 00 80 00 00 00 00 00 00 00 00
Request Power: Direction: APC  DSPB
Byte
Offset
Byte Name
Byte
value(s)
Byte Description
00
Start Token
7E
Generic message start identifier
01
Message ID
40
Unique message identifier
02
Sequence Number
01 – FF
Sequential message identifier
3-4
Checksum
0000 – FFFF
Checksum (2 bytes)
5-6
Payload Length
0000
Data length (2 bytes)
7-8
Pad
xxxx
Pad to word boundary (2 bytes)
Response example: actual bytes sent and bytes received from wavelength meter
using message 0x40, Request Power:
WRITE Length 9 bytes: 7E 40 03 52 03 00 00 12 00
READ Length 15 bytes: 7E 68 84 2F B1 06 00 20 A8 86 01 C7 3E 20 A2