HN-291D
Modbus Adapter Commands
When in Modbus mode, the following commands are available via WinCom24.
Command
Description
qp[0|1]
Protocol Mode
0 = Transparent mode. Non-Modbus mode
1 = Modbus mode. Supports encapsulation of data to ensure
continuous send-out on receiver side. Also supports the learning
of Modbus addresses.
qs[0|1...|8]
Serial Data Options
0 = No parity, 8 bit data, 1 stop bit (default)
1 = Odd parity, 8 bit data, 1 stop bit
2 = Even parity, 8 bit data, 1 stop bit
3 = No parity, 7 bit data, 2 stop bits
4 = Even parity, 7 bit data, 2 stop bits
5 = Odd parity, 7 bit data, 2 stop bits
6 = No parity, 7 bit data, 1 stop bits
7 = Even parity, 7 bit data, 1 stop bits
8 = Odd parity, 7 bit data, 1 stop bits
qw[0|1|2]
Adapter Wiring Mode
0 = Normal, “full wire” mode
1 = Three-wire mode (RX, TX, GND)
2 = Three-wire mode + DTR
qd[00..ff]
Only valid when qp = 1.
Sets the amount of time in 3ms increments that the adapter on the
receiving end will hold data from the transmitting HN-291D while
waiting for the end of the current Modbus packet. If this time expires
before the end of the Modbus packet arrives, then the data in the
receive buffer is output. If a gap in data occurs due to retransmission,
a Modbus error may occur. If the end of the Modbus packet arrives
before the time expires, the data is released when the end of packet is
received. This allows the first-byte latency due to keeping the
Modbus packet without gaps to be adjusted for the application.
Default value is 0D (36ms)
©
2000- 2004 Cirronet
™
Inc
41
M-0910-0002 Rev B