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7. How to use the communication interface
Response to a communication error
When BF500 in the communication open state does not understand a command or a parameter sent
from the host or finds an error in a command or a parameter, BF500 sends the following
communication error message as an echo back.
<BEL> ERR_message <CR> <LF>
01>
(
The underbar “_” means a space.)
The contents of the communication error message are as shown in the table below.
message
Contents of a communication error
COMMAND
Received an undefined command.
PARAM
Received a parameter whose data format is not supported on BF500
※
1
（
numeric value format, numeric value range
）
.
EXEC
Received a command while BF500 is not ready to accept a command.
※
2
※
1
※
2
Specific example includes when a temperature setting beyond the set temperature rangef of
BF500 is received.
Specific example includes when the communication start request “remote_n” command is
received from the host while the trouble detection mechanism of BF500 has detected an error
that cannot be automatically recoverd or during coomunication lock out.
Communication specification
Items
Specifications
Communication system
4-wire full duplex, EIA RS-422A compliant
Synchronization system
Asynchronous
Connection system
Multi-drop
※
1
Communication distance
Max. 500m
Communication rate (bit/sec)
*2
1200, 2400, 4800, 9600
Data length (bit)
8
Stop bit length (bit)
*3
1 or 2
Parity
No parity
Communication sign
ASCII code
Delimiter
<CR> <LF>
Communication ID
*4
Up to 10 from among 01 to 15 can be selected
※
1
※
2
※
3
※
4
Up to 10 BF500 can be connected to one host.
Default value is 9600 (bit/sec).
Default is 1 (bit).
Default is 01.
