User manual - DATA RECORDER SRD-99 and cooperating software
7.4.11.
”RS485 port settings” menu
This menu contains options to configure the RS-485 interface:
”Address”
- this parameter specifies the unit’s address, according to the Modbus protocol
(in the range of 0 to 99). If the address is set as 0, then the unit responds to
the FFh address.
”Baud rate”
- this option defines the RS-485 serial interface transmission speed.
8 possibilities are available:
”
1200
”, ”
2400
”,”
4800
”
,
”
9600
”, ”
19200
”
,
”
38400
”, ”
57600
”, ”
115200
” b/sec.
Default baud rate value is 115200 b/sec. Some RS-485 converters may not work
properly with this setting. In such a case set lower baud rate (according to converter
data sheet).
”Resp. delay”
- this parameter defines minimal (additional) delay between the Modbus
message and the answer of the device (received and sent via RS-485
interface). This additional delay allows the device to work with poor RS-
converters which do not works properly on baud rates higher than 19200. This
parameter can be set to one of values:
”stand.”
- device responds without any additional delay
”+10 ch.”
”+20 ch.”
”+50 ch.”
”+100 ch.”
”+200 ch.”
The unit response with additional delay equal to
transmission time of 10, 20, 50, 100 or 200 characters.
In the most cases parameter
”Response delay”
should be set to
”Stand.”
(no
additional delay). Unfortunately for some third party RS-converters
”Response delay”
should be adjusted experimentally. Table below contains most
frequently used values.
”Baud rate” parameter
“38400”
“57600”
“115200”
”Resp. delay” parameter
“+10 ch.”
“+20 ch.”
“+50 ch.”
Tab. 7.1. Settings of
”Resp. delay”
parameter
”Conf. change”
- this option allows the method of accessing unit’s configuration registers
through the RS-485 interface to be defined.
The following options are available:
”denied”
- configuration registers can not be set via RS-485 interface,
”allowed”
- configuration registers can be set via RS-485 interface.
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