RS485 Settings

UC100 supports to set up communications with RS485 via two ways: Modbus channels or Modbus RS485 bridge LoRaWAN®.

Basic Serial Settings

UC100 has one RS485 port for Modbus RTU device connection. The basic serial settings should be the same as RS485 terminal devices.



Parameter Description
Stop Bit

1 bit/2 bit is available.

Data Bit

8 bit is available.

Parity

None, Odd and Even are available.

Baud Rate

1200/2400/4800/9600/19200/38400/57600/115200 are available.

Execution Interval (ms)

The execution interval between each Modbus channel command.

Max Resp Time (ms)

The maximum response time that the UC100 waits for the reply to the command. If it does not get a response after the max response time, it is determined that the command has timed out.

Max Retry Times

Set the maximum retry times after the device fails to read data from RS485 terminal devices.

Modbus Channels

UC100 supports to work as a Modbus RTU Client (Master) to poll the data from the RS485 device and return the data to the network server.



Click to add Modbus channels, then save configurations.



Parameter Description

Channel ID

Select the channel ID you want to configure from 32 channels.

Name

Customize the name to identify every Modbus channel.

Slave ID

Set a Modbus slave ID of a terminal device.

Address

The starting address for reading.

Quantity

Set the number of registers to read. It can be configured to 1 or 2.

Type

Select the data type of Modbus channels.

Byte Order

Set the Modbus data reading order if you configure the type as Input register or holding register.

INT64/Double: ABCDEFGH, GHEFCDBA, BADCFEHG, HGFEDCBA

INT32/Float: ABCD, CDBA, BADC, DCBA

INT16: AB, BA

Sign

The tick indicates that the value has a plus or minus sign.

Fetch
Click to send a Modbus read command to test if the RS485 device can reply with the correct values.
Note: Do not click frequently to avoid the fetch failure due to the slow response of RS485 devices.

Example:



Modbus RS485 bridge LoRaWAN®

UC100 supports to work as a relay to set up the communication between the server and RS485 devices. There are two pass-through modes:

Active Pass-through: the network server can send any command to the RS485 device and the RS485 device can only react according to server commands.



Two-way Pass-through: not only can network server send any command to the RS485 device, but also the RS485 device supports transmitting the data to the network server actively.



Note:

When Two-way Pass-through is enabled, Modbus channels can’t be used and the corresponding IF-THEN command will not work.



Parameter Description

Modbus RS485 bridge LoRaWAN®

Enable or disable the Modbus RS485 bridge LoRaWAN® feature.

Pass-through Mode

Select from Active Pass-through or Two-way Pass-through.

Port

The communication port between the RS485 device and the network server.

Range: 2-84, 86-223.