Each register uses 8-bit data. The register output values are the binary
totals for each bit shown in Figure 2.6.1-1.
Table 2.6.1-1 Register Bit Binary Conversion Values
Bit
Binary
value
0
1
1
2
2
4
3
8
To read the status byte register, set the service request enable register.
The logical product of these two registers is read by *STB .
Each standard event register has a corresponding enable register. The
logical product of the event and enable registers is obtained and the
logical sum of this result + 1 bit is output at bit 5.
Questionable Status Register
This register is reserved for future use. It is not used.
Message Queue
The message queue is always empty, so the response message from the
instrument can be sent immediately.
Up to 12 messages from the PC can be spooled.
Error Queue
Up to 12 error messages from the instrument can be spooled.
2.6
Checking Instrument Status
Bit
Binary
value
4
16
5
32
6
64
7
128
2
2-11