INFICON Cygnus Thin Film Deposition Controller - Manual (Page 141)

5 - 37
IP
N 07
4-
37
9-
P1
K
Cygnus Operating Manual
5.4.6 Negative Response Error Codes
An error code in the form of a single ASCII character is returned when a command
results in an error. There are two types of Error codes: a Packet Error Code or a
Response Error Code. Both are described under section
section 5.3.2.2,
Response Packet (Instrument to Host Message), on page 5-6 .
5.5 Sample Cygnus Commands
The following illustrate examples of typical message streams.
5.5.1 Remote Communications Example — Updating a
Channel’s Rate Parameter
An example of setting the Rate parameter to 10.00 A/s in Channel 3 by Remote
Communication is shown below.
The Rate parameter is changed by a UC command, since it will Update the
parameter value of a Channel.
The Rate parameter is a "Float" data type, and is a 32 bit number.
The Character "U" = 0x55 (hexadecimal 8 bit value)
The Character "C" = 0x43 (hexadecimal 8 bit value)
Rate Command ID is 20 = 0x14 (hexadecimal 8 bit value)
Channel 3 = 0x03 (hexadecimal 8 bit value)
10 (decimal) = 00002041 (hexadecimal floating point 32 bit value in LSB to MSB
order)
Putting them all together builds the 8 byte message shown as a byte message in
hexadecimal:
5543140300002041
Calculate the message checksum = {(sum of all bytes in the message) modulus
0x0100}
Checksum = {0x55 + 0x43 + 0x14 + 0x03 + 0x00+ 0x00 + 0x20 + 0x41) modulus
0x0100}
Checksum = {(0x0110) modulus 0x100}
Checksum = 0x10
Now to send the message, put a two byte length (LSB, MSB) ahead of the message
and a one byte checksum after the message.
0800554314030000204110