Fluke 45 - Manual (Page 77)

45
Users Manual
5-18
Table 5-7. Description of Bits in the Status Byte Register*
Bit No. Name True (Set to 1) Condition
0
1
2
3
4
5
6
7
Not used.
Not used.
Not used.
Not used.
Message Available (MAV)
Event Status (ESB)
Master Summary Status† (MSS)
Not used.
Always set to 0.
Always set to 0.
Always set to 0.
Always set to 0.
Data is available in the output buffer. Bit set to 1
when response to query placed in output buffer. Bit
cleared (set to 0) when output terminator sent to
host.
One or more of enabled events in the Event Status
Register have occurred. To determine which events
have occurred, send the meter "*ERR?" to read the
Event Status Register.
Set to 1 if any enabled bit in the STB (MSS) register
is set to 1, otherwise set to 0. Status of MSS bit
returned by STB? query command.
Request Service (RQS) Set to 1 if service requested
from front panel or MSS set to 1. Status of bit
returned by serial poll, which clears RQS.
Always set to 0.
† As read by *STB? command. If the Status Byte Register is read by a serial poll, bit 6 is returned as RQS.
Service Request Enable Register
The SRE Register is an 8-bit register that enables or disables (i.e., masks) corresponding
summary messages in the Status Byte Register.
The meter may be programmed to make a service request on errors or when output is
available. Conditions that trigger a service request are specified by writing a binary-
weighted value to the SRE Register, using the "*SRE" command.
EXAMPLE EXPLANATION
*SRE 16 Enables the generation of an SRQ when bit 4 (MAY) in the Status
Byte Register is set to 1. 16 is the decimal equivalent of 00010000
binary. This means that bit 4 in SRE Register (that corresponds to the
MAV bit in the Status Byte Register) is I and all other bits are 0.
EXAMPLE EXPLANATION
*SRE 48 Enables the generation of an SRQ when bits 4 and 5 (MAV and
ESB) in the Status Byte Register are set to 1. The binary equivalent
of 48 is 00110000, indicating that bits 4 and 5 are set to 1.
If any bit in the SRE is set to 1, the RQS bit (bit 6) in the Status Byte Register is enabled,
meaning a service request can be generated when the appropriate bits in STB become 1.
At power-up or on any device-clear command, the SRE Register is set to 00 (decimal).
Use the "*SRE?" query (see Table 5-8) to read the SRE Register. The meter returns a
binary-weighted integer that represents the enabled bits in the register. (The value of bit