JUMO 902931 Wtrans Receiver with Wireless Data Transmission Operating Manual - Manual (Page 67)

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9 Term definition
9.1.3 RS485 interface
Baud rate
Transmission speed of the RS485 interface.
If a master (PC or PLC) is connected to the interface, select the same baud rate on the master
side.
Data bits/parity/stop bits
RS485 interface data format
If a master (PC or PLC) is connected to the interface, select the same data format on the master
side.
Minimum response time
The receiver adheres to the minimum response time following a data request before sending a
response. The response time is required by the master for the RS485 interface in order to
switch the interface drivers from transmit to receive.
Device address
The receiver can be accessed with the set unit address via the RS485 interface. For this inter-
face, the device address of the receiver may only appear once within a connection (several de-
vices on one bus).
Customer replacement actual values
The current display values can be read out from a receiver by a Modbus master via the ad-
dresses (hex) 00E7 to 0105.
In the event of an error (timeout, overrange, underrange, etc.) it reads a very large value (e.g.
9.0 × 10
37 for wireless timeout – see chapter 2.9.2 of B 902931.2.0 "Modbus interface descrip-
tion") via these addresses.
The new customer replacement actual values for the addresses (hex) 0407 to 0425 are intend-
ed for all users who are unable to evaluate these large values with their Modbus masters.
In a normal case (no errors present), the customer replacement actual values contain the same
values as the display values. In the event of an error, the customer replacement actual value
programmed in the receiver is transmitted. This allows the user to identify errors.
TIP!
Modbus B 902931.2.0 interface description
(The Modbus interface description is available as a free download on the Internet
at www.jumo.net.)
CAUTION!
These settings only relate to the RS485 interface.
The setup connector is operated independently of these parameters with the fixed settings for
transmission speed: 9600 baud, data format: 8n1, minimum response time: 0 ms, and device
address: 1.