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Electromagnetic Flowmeter BFM921
5.1.9.2 RS232 bus properties
To transfer the data using RS232 bus, 8N1 data format is used, i.e. each data word includes 8 bits, no parity
and one stop bit. Communication speed can be set using menu. Address is not used in RS232 mode.
Baud rate
Data bits
Stop bit
Parity
5.2 Command syntax
Communication between flowmeter and computer consists of a flow of periodically alternating commands
type command-response or query-response. Command is always a text followed by parameter and ended by
control sign <cr>. Response is always ended with control sign <cr>.
There are three types of responses:
1) Parameters value – response to a query
2) Ok – response to a command
3) ErrX – in case that command has wrong format. Where X is error code from the table below:
Error code
Meaning
1
Unknown command
2
Parameter out of range
3
Value cannot be set
4
Value cannot be read
5
Unknown parameter
6
Parameter too low
7
Parameter to high
8
Number as parameter is required
9
Access denied – use appropriate password
10
Wrong value of calibration point
11
Password locked – six unsuccessful attempts to enter password. Setup menu is blocked
for 20 minutes.
Commands described in this chapter can be issued through both buses (RS485 and RS232). The only
difference is, that before all commands for RS485 bus is identification in form "#00". Where '#' is the
command prefix and "00" is flowmeters address 0 in hexadecimal form. For flowmeter with address 1 it's
identification is "#01". Flowmeter answers are prefix in form ">00" for flowmeter 0, ">01" for flowmeter 1
etc.
Modbus protocol is explained in independent document.
32
User setup
Fixed
Table 12 : USB/RS232 properties
Table 13 : RS232 error codes
1200 to 115200 Bd
8
1
none
Operation manual
BASI
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