Promax MO-160 Manual De Usuario página 93

USER'S MANUAL. MO-16X
In order to ensure an error-free communication between the computer and the
modulator connected over an Ethernet network, the port settings of the virtual serial port
are always the following:
Rate: 19200; Data bits: 8; Parity: None; Stop bits: 1; Flow control: None
The MO-16X accepts remote commands at any time as long as the instrument is
on. It is not necessary to put the MO-16X in a special remote control mode.
The communication protocol is as follows:
1) The MO-16X transmits an XON code (0x11) every second. This tells any
device that might be listening on the other side of the virtual serial connection
that the modulator is ready to receive data.
2) Control commands sent to the modulator have the following format:
a. Initial character "*" (0x2A).
b. Set of characters that form the command.
c. End character CR (carry return, 0x0D).
3) Once a command has been sent, an XOFF will be received, indicating that
the transmission of any new command must be held on until the current one
is completed.
4) Next, if the format of the sent message is correct and its execution was error-
free, an ACK (acknowledged) should be received. Otherwise, a NAK (not
acknowledged) will be sent back by the modulator.
5) If the control command was a query, the reply should be received at this
point.
6) Once the message has been processed, the MO-16X will issue an XON to
indicate that it is ready for new commands.
A typical communication timing diagram would look as follows:
Tx/Rx PC
⇐
⇒
⇐
⇐
⇐
⇐
Note: That all characters are transmitted in ASCII code.
04/2008
MO-16X
XON Equipment ready for command
*?NAM<CR> Command issued by the controller
XOFF Command received indication
ACK Command accepted / understood
WAIT... Execution delay
*NAMO-160<CR> Command answer sent
WAIT Usually some small delay
XON Equipment ready for command
Page 33