Promax HD Ranger Lite, User Manual

Page: 160 / 184

34 July 2015
3
A4.3
Operation Mode
The
HD
RANGER
Lite
accepts remote commands at any time, which the
instrument is on. That is, it is not necessary to put the instrument in special
remote control mode; rather, this mode is selected immediately when it detects a
complete command during the time necessary for its execution. The protocol
communication is as follows:
1.- HD
RANGER
Lite transmits a XON code (11H) every second. The aim is
to indicate to any possible remote device that the equipment is ready to
receive data.
2.- At this moment, data streams can be sent it. Each data stream is
composed by:
a. Stream beginning: ‘*’ (code 2AH).
b. Set of characters that describe data message.
c. CR (carriage return, code 0DH).
3.- Once a data stream has been sent, will be received a XOFF (code 13H)
indicating that the transmission is stopped.
4.- Next, in case of correct message an ACK (acknowledge, code 06H) is
expected or a NAK (not acknowledge, code 15H) in the opposite case.
5.- If the sent message requires answers it will be sent at this moment.
6.- Once completed the data stream transmission, the
HD
RANGER
Lite
will
send a XON (code 11H) indicating that already it is prepared to receive a
new data stream.
A typical communication chronogram would be as follows:
PC (REMOTE CONTROLLER) HD RANGER
Lite
1) <------ XON
2) *?TV<CR> ------>
3) <------ XOFF
4) <------ ACK 5
5) <------ *TV0<CR>
6) wait…
7) <------ XON
(all characters are transmitted in ASCII code).