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Model 880 DEPOSITION CONTROLLER
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SECTION 6.XX
e page 194 of 276 ^
RS-232 Protocol
The RS232 protocol parameter selects one of the two RS-232 protocols available. A 0 will select
the Sycon protocol and a 1 will select the ASCII protocol.
Optional: Addresses
<not implemented> If you use an optional communications card, you will need to assign bus
addresses.
Optional: Checksum Mode
<not implemented> If the optional communications card is installed, this parameter allows an
optional checksum character to be used with the message packets.
SECTION 6.4 Industrial Interface Option
<not implemented>
SECTION 6.5 Response Format
All commands received by the Model 880 will return a response. The minimum response (not
including protocol dependent characters) is a single ASCII character. This character indicates two things.
First the success or failure of the command which was sent. One of six result types is returned, to
indicate success (AOK), illegal command token (Groups 1..16), illegal data value (number out of range for
command), illegal syntax (something other than required = sent after command token), inhibited operation
(changing the film number while depositing for instance) and I/O sequencing error.
Second, the returned response character reports the power on reset status of the Model 880. Each
of the four response codes (see below) is modified after a reset until the ? command resets the power failure
flag. In this way each response message informs the host as to the occurrence of an instrument reset since
the last exchange. The reason this is done is so that in every communication exchange a power on reset can
be detected and the correct exception processing be performed via host software, without special polling
overhead.
Response character Power Lost No Reset
Message AOK B A
Illegal Command G F
Illegal Data Value I H
Illegal Syntax K J
Inhibited Operation M L
I/O Sequencing Error O N
Table 6.7: Response Character Table.
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SECTION 6.6
Result Codes Returned: The first letter of the reply message sent from the Model 880 to the host
computer is from the set of result codes detailed below. For each type of result one of two reply
characters is returned depending on the nature of the power up acknowledge flag of the
instrument. The second letter of the two for each type of result is returned after any previous
power failures or resets (such as when the unit is first powered up). Once this condition is
recognized and handled (bringing the host and the Model 880 into synchronization) and the host
sends the '?' command to the Model 880, then the power loss/reset is acknowledged by the host
and replies from the Model 880 are then prefixed with the first letter of the particular response
type.
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