Appendix B - Network Terminal RS-232 Interface Protocol Format
B-4
P/N 8040375G001
C
HELIX TECHNOLOGY CORPORATION
-
TI
CRYOGENICS
The following is an example of a typical exchange:
Host Sends query to get back On-Board Module Version Information for
Pump #1
Checksum of Pump Address and Data Field
Bits 76543210
Sum of
50
01010000
30
00110000
31
00110001
40
01000000
Equals
11110001or Hex F1
Bits 7 & 6 aligned for
X0R
00000011
X0R result
11110010
Mask D5, D0 00110010
Addend ’0’
00110000
Final Chk
01100010 Hex 62, ASCI ’b’
Slave sends reply of AP A2.01, meaning no error, Pump version A2.01.
Flag
Pump
Address
Data
Field
Checksum
Terminator
ASCII
[$]
[P] [0] [1]
[@]
[b]
[CR]
Hex
[24]
[50] [30] [31]
[40]
[62]
[0D]
Flag
Data
Field
Checksum
Terminator
ASCII
[$ ]
[A ] [P ] [ ] [A ] [2 ] [. ] [0 ] [1 ]
[a ]
[CR]
Hex
[24]
[41] [50] [20] [41] [32] [2E] [30] [31]
[61]
[0D]
