Teledyne ULTRAFLOW 150, Руководство по эксплуатации, Страница: 40 / 162

ULTRAFLOW 150 GAS FLOW AND TEMPERATURE MONITOR
internal jumper located on the Mother Board. However, the RS-485 port
communication protocol does not support addressability.
The communication parameters of both ports are fixed. They are listed in Table
6-1.
Table 6-1
BAUD RATE DATA BITS STOP BITS PARITY
9600 8 1 N
The protocol operates in a polled mode only, i.e., the user must issue a request in
order for the Enhanced Remote Panel to transmit data. Broadcast mode is not
supported.
The user request protocol is an ASCII string of the format
nnnx<CR>
where nnn is a number from 1 to 511 corresponding to the requested variable,
<CR> is the carriage return character and x is one of two command characters (?
or $). The nnn values of 255 and 511 have special significance (see below). All
other characters are ignored and will cause the Enhanced Remote Display serial
port to respond with an error message. A time delay of more than 10 seconds
between characters will cause the previously sent characters to be discarded.
Table 6-2 is a summary of the possible user requests followed by some examples.
Table 6-2
USER REQUEST ENHANCED REMOTE DISPLAY SERIAL PORT RESPONSE
nnn?<CR> Send variable nnn
255?<CR> Send all TIE1 variables sequentially
511?<CR> Send all TIE2 variables sequentially
nnn$<CR>
Send 15 consecutive variables starting with variable nnn-14 and
ending with nnn
RESPONSE FORMAT EXAMPLES
REQUEST:
1?<CR>
RESPONSE: 1 TIE1_DATE: 16-Jul-02<CR><LF>
REQUEST: 123?<CR>
RESPONSE: 123 StdFlowVolInstTIE1A: -0.736057<CR><LF>
REQUEST: %67*<CR>
RESPONSE: UNRECOGNIZED COMMAND<CR><LF>
REQUEST: 534?<CR>
RESPONSE: INVALID VARIABLE NUMBER<CR><LF>
6-4