232DTT1795 Manual
Chapter 4
7
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Chapter 4. 232DTT Commands
The DTT commands can be issued from a program, or even
typed in from a simple terminal program. Two files are included on
the 232DTT disk to help learn the DTT commands. A sample
program with source code written in QuickBASIC 4.5 demonstrates
all DTT functions and a simple terminal program is also included. In
addition, a simple data logging utility is provided which allows data to
be logged to a file. Appendix A demonstrates how to communicate
with the DTT from the terminal program. A decimal/ASCII
conversion table is included in Appendix B.
Read Temperature
Command
: !0RT
Arguments
: none
Response
: temperature reading in 9 bit two’s complement format
(shown in boldface)
Dec. Example:
!0RT
<0><46>
ASCII Example:
!0RT
<NUL>.
Description:
The decimal 0 (NUL) followed by decimal 46,
equivalent to an ASCII “
.
” converts to a temperature of +23
°
C.
Read Status
Command:
!0RS
Arguments
: none
Response
: contents of 8 bit status register (shown in boldface)
Dec. Example:
!0RS
<0><66>
ASCII Example
: !0RS
<NUL>B
Hex. Example:
!0RS
<0><42>
(since this is an eight bit register, it
may be helpful to use hex representation)
Description:
The first character (NUL) has no meaning in this
response. Bit 1 is set, indicating normal operation. Bit 5 is clear
indicating the low thermostat has not tripped. Bit 6 is set, indicating
THIGH has tripped since the last !0SC command.
Table 3. Status Register Description
Bit 0
X (don’t care)
Bit 1
operation
Bit 2
X
Bit 3
X
Bit 4
X
Bit 5
Low Thermostat Tripped Flag
Bit 6
High Thermostat Tripped Flag
Bit 7
X
