Hioki SM7810, Инструкция по эксплуатации, Страница: 30 / 69

4.5 Communication Methods
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RS-232C reads the status bytes to find out the status of the instrument.
The instrument adopts the IEEE488.1-1987 defined status model for parts
related to the serial polling performed by the service request function. A trigger
for generating a service request is called an event.
The Status Byte Register contains information about the event registers and the
output queue. Required items are selected from this information by masking with
the Service Request Enable Register. When any bit selected by the mask is set,
bit 6 (MSS; the Master Summary Status) of the Status Byte Register is also set,
which generates an SRQ (Service Request) message and dispatches a service
request.
Status Byte Register
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
ERR
RQS
ESB MAV DSB
unused unused unused
MSS
& & & & & & &
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
ERR x ESB MAV DSB
unused unused unused
Logical
sum
Status Byte
Register (STB)
Service Request Enable
Register (SRER)
Service Request
occurrence
Output Queue data information
Standard Event Register Information
Each of these bits corresponds to a specific event register
Overview of Service Request Occurrence
For RS-232C, bit 4 (MAV message available) of the status byte register is not
set.