Service Requests - Motorola R-2002A Manual

22-43. The format of the error message is:
ERROR nn (CR)(LF)
The two digit number nn defines the error condition as listed in table 22-5. The carriage return (CR) and line
feed (LF) characters are the termination sequence used by analyzer whenever it transmitts information. All
characters are ASC ll coded.
Table 22-5. Error Messages
Error Code Condition
00
Data requested without trigger
01 Invalid mnemonic prefix
02
One character mnemonic (not T)
03 Invalid mnemonic suffix
04
Exponent overflow
05 Data underflow
06 Data overflow
07
Data transmitted, not allowed
08 Invalid data
09 RF input power exceeded
10 Level or mod control error
22-44. To effectively uti I ize the error message capability of the analyzer it is necessary to address the unit as a
talker after the transmission of each command string. The bus controller must then be programmed to
recognize the error message and to decode the error number. A successful data transmission will send back an
error code 00 when addressed as a talker. The controller should be programmed to ignore error 00 and to
display any other error to the operator. Of course if a valid output command followed by the trigger command
was sent, the talker address will result in the requested data being output to the controller.
22-45. Service Requests. There are only two conditions that will cause the analyzer to generate a service
request (SRQ) on the bus. If a SRQ is generated it must be cleared by a serial poll of the analyzer. The serial poll
is a bus command which results in a data byte being sent to the controller from the analyzer. The data byte
indicates the cause of the SRQ. Table 22-6 lists the SRQ causes and the corresponding serial poll data.
Table 22-6. SRQ Data
Return Data
Condition Binary HEX DEC
Depressing Cursor
01000001 41 65
Down Key
RF load over 01000010 42
66
Temperature
22-10