Geolux RSS-2-300W, User Manual

RSS-2-300W User Manual

19

RSS-2-300W Non-Contact Surface Velocity Radar

RS-485 protocol

 - Selects the communication protocol to be used on RS-485 half-duplex 

interface. HS protocol is a simple request-response protocol for the simplest applications. 

Modbus RTU protocol is a standardized protocol which is commonly used in automation and 

instrumentation as it provides all measurements with detailed diagnostics of device operation 

and the possibility to change the instrument’s operating parameters.

#set_485_proto=modbus_rtu

#set_485_proto=hs

Device ID

 - Configures the device (slave) ID to be used on RS-485 interface protocols (Modbus 

RTU or HS). Both protocols use request/response format and allow multiple instruments to 

be connected on the same bus. When a remote master transmits the request message, it will 

use the device ID as a device address. All instruments will receive the request, but only the 

instrument with matching device ID will answer to the received request.

#set_can_id=<0-99>

Modbus settings

 - Configures the parity and number of stop bits used in communication. 

Parity is used in serial communication for basic error detection. When parity is set to none, 

no parity is used, and no error detection is possible on bit level. When parity is set to odd 

parity, an additional bit is added to the communication that will be set to 1 when there is 

odd number of bits with value 1 in the 8-bit payload byte. Similarly, when parity is set to even 

parity, an additional bit is added to the communication that will be set to 1 when there is even 

number of bits with value 1 in the 8-bit payload byte. In general, all bytes on the receiver side 

where the parity bit is not matching the message will be discarded. Default setting on most 

devices that use Modbus is even parity. Stop bits are added to the end of each data byte 

transferred over serial communication, to allow pause between two bytes. The default setting 

is even parity and one stop bit.

#set_485_modbus_type=1 

(no parity, two stop bits)

#set_485_modbus_type=2 

(even parity, one stop bit)

#set_485_modbus_type=3 

(odd parity, one stop bit)

4-20 mA output 

 - This parameter is used to select the value that will be presented on the 

4 - 20 mA output. When velocity is selected the output current will be proportional to the 

measured velocity. When selecting none 4-20 mA output will be disabled.

#set_an420_type=velocity

#set_an420_type=none

4-20 mA min.

 - To configure the 4-20 mA output range, the minimum measured value which will 

correspond to 4 mA analog output needs to be set. The value is set in the currently configured 

measurement unit. Example: if values measured by the instrument are expected to be within 

the range of 700 mm/s to 1500 mm/s, it is recommended to configure the minimum value to 

slightly below 700 mm/s (for example 500 mm/s). Alternatively, if the resolution is not critical, then 

minimum value for 4-20 mA output can be left to the instrument minimum of 0 mm/s.

#set_420_min=<value>