INFICON MDC-370 Thin Film Deposition Controller - Manual (Page 158)

MDC-370 DEPOSITION CONTROLLER
Parameter Name Length (bytes) Allowable Range
Layer Material Name 10 All ASCII Characters
Number of Data Point Sets 2 (1-27,000)
Total 12 bytes
Following the above message will be a number of messages containing the data
point set data. The following table shows the data format of the data point set
message type for one data point set:
Parameter Name Length (bytes) Units
Message Number 2 1-1125
Thickness 3 Angstroms
Rate 3 0.1 Angstroms/second
Power 2 0.1 %
Rate Deviation 2 0.1 %
Total 12-242 bytes
Since the MDC’s message length is limited to 249 bytes, a data point set message
will contain up to 24 data point sets for a total of 242 bytes. The controller will
send as many messages as needed to complete the process log layer. To
determine the number of messages to expect, you just divide the number of data
point sets by 24. And, if there are any left over, then add one more to the result.
Very long layers can result in over 1000 messages, which will take up to two
minutes to send. This last message will contain the remaining data point sets to
complete the layer. A message number is included in each message to ensure that
all messages are received and are in order.
Format: Header, Address=1, Instruction=37, Length=3, 1 byte Log#(1-16), 2 byte
Layer#(1-999), Checksum
Example: To instruct the controller to send the layer 1 of process log 5 the
computer would send:
Chr$(255)+Chr$(254)+Chr$(1)+Chr$(37)+Chr$(3)+Chr$(5)+Chr$(0)+
Chr$(1)+Chr$(209)
39. Remote activation of controller (Code #38)
This instruction initiates a remote action. The possible actions are shown in the
following table:
COMPUTER INTERFACE 11-28