SRS Labs QMS 100 Series, Руководство пользователя

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3-24 Programming the RGA ECU
SRS QMS Gas Analyzer
The RGA is turned on and, after all the internal checks are performed, the green Power LED and the
Error LED are turned on. The red LED signals the operator that a problem was detected. A 24V P/S
error is not expected since the Power LED is on. The ER? command returns a STATUS byte with bit 4
set, pointing to a quadrupole mass filter problem. The command EQ? is used to read in the QMF_ERR
byte. Bit 7 is found set indicating that the RF driver is unable to set the maximum RF value available to
the RGA (Error code RF7 in Troubleshooting Chapter). A quick visual inspection of the RGA ECU
shows that the ECU is not pushed all the way into the probe and no actual connection exists between
the rods and the RF driver.
This error is also immediately reported by the RGA Windows software as Error Code: RF7, and the
RGA Troubleshooting section can be consulted to solve the problem.
Error Diagnosis Example #4
The user notes that the Error LED flashes every time the ID? command is sent to the RGA and the ID
string is never returned (i.e. receive timeout). The STATUS byte returned by the ER command has the
bit 0 set as expected for a communications problem. The specific communications problem is diagnosed
using the EC? command. Bit 0 of RS232_ERR is found set indicating that a bad command is being
detected by the RGA. The user checks the communications program and finds out that, due to
mistyping, the IM? string is being sent to the RGA instead of ID?. The problem is easily corrected.
Error Checking Programming tips
•
Keep a close eye on the Error LED’s while programming the RGA. Diagnose problems as
soon as they are detected.
•
Even though a lot of internal checks are performed by the microprocessor, not all possible
internal error conditions are accounted for.
•
The values of the Error Bytes often change after an Error Byte query command is executed.
Some query commands update the byte value after performing a fresh test on the hardware,
while others clear error bits, after they are read, to provide a clean error-reporting slate.
Please see the Error Reporting Commands list for details.
•
It is good programming practice to check the value of the STATUS byte whenever it is
returned at the end of command execution.
•
In cases were a hardware error is reported at the end of a command attempt the command
one more time before declaring a hardware problem.