User`s manual

Chapter 6 123
Advanced Operations
Status Reporting
Status Byte Register
The Status Byte Register is an 8-bit register that is used to summarize
the Summary Messages from all the register groups in the Test Set, and
the Request Service (RQS) or Master Summary Status (MSS) messages.
The contents of the Status Byte Register, referred to as the status byte,
can be read by the Active Controller to determine the condition of each
of the register groups. The Summary Message from each register group
is assigned to a specific bit position in the Status Byte Register as
shown in Figure 6-2. If the Summary Message from a particular
register group is TRUE, logic 1, its assigned bit in the Status Byte
Register will also be TRUE. If the Summary Bit from a particular
register group is FALSE, logic 0, its assigned bit in the Status Byte
Register will also be FALSE.
NOTE A Status Register Group Summary Message Bit may be summarized
indirectly to the Status Byte Register through a Status Register Group
which is summarized directly into the Status Byte Register.
Figure 6-2 Status Byte Register
Status Register Group
Status Register Group
Status Register Group
Status Register Group
RQS
MSS
6 Status Byte Register 1 07
Service Request Enable Register
Service Request Generation Function
MSS
Service Request
Interface Message
SRQ
Enabled Summary Message
Request Service Message
RQS
ch4drw01.ds4
Summary Message Bits