Alpha Moisture Systems dewTEC DS2000, Инструкция по эксплуатации

Страница: 25 / 29

5.3.2 Message Form 2
This message implements a Parameter Read operation. The message from the master device is
of the form:
Laap?*
where
aa is the address (a two digit hexadecimal number)
p is a single character parameter identifier (see table below)
The reply, if the Parameter Read operation is successful, is of the form
LaapnnnnA*
where
aa is the same address as in the received message
p
is a single character parameter identifier (see table below)
nnnnn is the data (a five digit hexadecimal number)
If the specified parameter is invalid (e.g. not applicable to the addressed instrument), the reply
is of the form:
Laap00000A*
where
aa is the same address as in the received message
p is a single character parameter identifier (see table below)
Identifier Hex. Parameter Range
: 3A Dewpoint Depending on factory set range
; 3B Total Value -19999 to 99999
< 3C Maximum Dewpoint -19999 to 99999
= 3D Minimum Dewpoint -19999 to 99999
> 3E Elapsed Alarm 1 Time 0 to 60000
E 45 Alarm 1 Dewpoint Range Maximum to Range Minimum
F 46 Alarm 2 Dewpoint Range Maximum to Range Minimum
5.4 Error Conditions
If a slave detects a syntax error or parity error, it will not reply to the message; the master
device should make up to two retries, applying the two second No Reply timeout in each case.
Parameter read operations with parameter identifiers which are not applicable to the addressed
instrument, will have no effect and a positive acknowledgement will be returned.
dewTEC DS2000 User’s Manual Page 19