D-12 DDC Emulation Commands Model 6485 Picoammeter Instruction Manual
Figure D-3
U2 Status word
Status Byte Format
The status byte contains information relating to data and error conditions within the instru-
ment. When a particular bit is set, certain conditions are present. Table D-2 lists the mean-
ings of the various bits, and Figure D-4 shows the general format of the status byte, which
is obtained by using the SPE, SPD polling sequence.
If the status byte is read when no SRQ was generated by the Model 6485 (bit 6 is clear),
the current status of the instrument will be read. For example, if a reading was done, bit 3
would be set.
When an SRQ is generated by the Model 6485, bit 6 of the status byte will be set. If the
SRQ was caused by an error condition, bit 5 will also be set along with one of the error
condition bits (B0, B1, or B2). Only the error that caused the initial SRQ will be defined
by the status byte.
If the SRQ was caused by a data condition, bit 5 will be clear and the appropriate data con-
dition bits (B0, B1, B3, and B4) will be set. If the reading overflow condition caused the
SRQ, then only the reading overflow bit will be set.
After an SRQ, the status byte will remain unchanged until it is read.
PREFIX
Buffer Size
Set using I command
Reading Quantity
Number of readings
currently stored in buffer.
Delimiter (,)
485xxxxx,yyyyy
STATUS (BUFFER SIZE AND READINGS STORED) FORMAT
To Next Page
Loading...
Need help?
General
