Status Reporting Commands - Isotech TTI 7 PLUS User Maintenance Manual/Handbook

Status Reporting Commands

There are five groups of registers involved.
The Questionable Data and Operation groups each consist of three registers:
- The Condition Register contains the current status of the instrument and is continuously updated. The
register value can be read at any time using the appropriate query (?) command.
- The Event Register detects '0' to '1' transitions in the Condition Register and the appropriate bit is set. The
register value can be read at any time using the appropriate query (?) command. Reading an Event Register
results in all the bits of that register being cleared, and the corresponding bit of the Status Summary Byte is
also cleared.
- The Enable Register is a mask which allows any of the bits from the Event Register to set the appropriate bit
in the Status Byte. Setting an enable bit to '1' enables the event bit; clearing the enable bit inhibits the
corresponding event bit. The register value can be read at any time using the appropriate query (?)
command.
The Standard Event group is similar, but consists only of the Event and Enable Registers. There is no Condition
Register.
The Output Buffer stores a single line message to be transmitted to the bus. This can be up to 80 characters long.
The message is normally the result of a query (?) command.
The Status Byte group are used to read a summary of the other registers.
Note that all Event Registers are cleared after reading, but the Condition Registers, Enable Registers, and Status Byte
are left unchanged after reading.
Page 35 of 44
TTI-7 Iss.02 – 06/11