FTS MAXI-COOL, Руководство оператора, Страница: 45 / 66

Maxi-Cool
EDC Programmer’s Reference
Rev 007, 04/12 37
© SP Scientific 2012
Error Message: receipt of a message that is syntactically incorrect, exceeds 2.
system limits, or is otherwise faulty (such as Parity Error), will result
alternately in an error message.
Parameter Message: in response to a query, the parameter and its value will 3.
be returned to the host. If multiple value/status queries are transmitted in a
single statement, the multiple replies will be transmitted on multiple lines (
i.e .,
separated by carriage returns).
Terminator Character: All messages will be terminated by an exclamation 4.
point ("!") (ASCII 033 decimal / 21 hex). This character is appended to a
single-line message, including "OK", or to the end of the last line of a multiline
message if the host has transmitted queries.
The controller is capable of "full duplex" operation; i.e ., it is capable of 5.
receiving data while transmitting data. However, it is strongly suggested that
the host wait for the message “OK” and the exclamation point ("!") before
proceeding to its next transmission, to ensure correlation between information
sent and the replies.
The Command POLL has been provided as a non-operative command (similar to an
assembly language NOP or BASIC language REM) to verify establishment of
communications between the host and the slave. The POLL command will have no
effect on the state of the controller or its system, and can result in an error only if the
RS 232 connection itself is not correct (
e.g ., wrong BAUD rate, parity error, etc .).
Once the POLL command has been issued, and the string "OK!" has been received
by the host, the software may be assumed to be synchronized.
User software should be configured to transmit a message (received data), receive
the reply (transmitted data), and verify the integrity of the exchange before proceeding
to the next transmission.