|
Name |
Description |
Value range |
|---|---|---|
|
Basic settings |
||
|
Enable Modbus gateway |
If set to “Yes”, the Modbus gateway functionality is enabled for the serial port. Each serial port of the device has its own Modbus gateway definitions. |
No, Yes |
|
Serial settings |
||
|
Serial port |
Defines the serial port that the device uses for Modbus serial communication. The possible settings are “RS1”, which selects serial port 1 (RS-232 console/application port) and “RS2”, which selects serial port 2 (RS-232/422/485 application port). If a single serial port or RS-422/485 is required, port 2 is recommended. If Port 1 is used, the console switch of the device must be in the Application position. DIP switches below the DB-9 serial connector specify the RS-232/422/485 settings of Port 2. |
RS1, RS2 |
|
Serial settings |
||
|
Speed |
Defines the serial port speed for Modbus communication in bps. The optimal speed depends on the connected Modbus equipment. |
300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 |
|
Data bits |
Defines the number of data bits used in Modbus serial communication. The required number depends on how many data bits the connected Modbus equipment supports. Generally Modbus RTU communication uses 8 data bits and Modbus ASCII communication uses 7 data bits. |
5, 6, 7, 8, Auto |
|
Parity |
Defines the parity method used in Modbus serial communication. If set to “None”, no parity method is used. If set to “Even”, an even parity bit is generated and inspected. If set to “Odd”, odd parity bits are generated and inspected. |
None, Even, Odd |
|
Stop bits |
Defines the number of stop bits used in Modbus serial communication. |
1, 2 |
|
Use HW handshaking (CTS/RTS) |
Enables CTS/RTS handshaking if set to “Yes”. |
No, Yes |
|
Gateway mode |
||
|
Gateway mode |
If set to “Network master to serial slaves”, the slaves are on the serial side. |
Network master to serial slaves |
|
Protocols |
||
|
Serial protocol |
Defines the Modbus protocol that serial devices use in serial communication. The possible settings are Modbus RTU protocol and Modbus ASCII protocol. ModbusRTU is recommended because it is more efficient. |
ModbusRTU, ModbusASCII |
|
Network protocol |
Defines the TCP/IP and Modbus protocol used on network communication. Possible protocols are Modbus TCP protocol over TCP, Modbus RTU protocol over TCP, Modbus RTU protocol over UDP, and Modbus ASCII protocol over UDP. |
ModbusTCP, ModbusRTU over TCP, ModbusRTU over UDP, ModbusASCII over TCP, ModbusASCII over UDP |
|
Framing |
||
|
Slave response timeout |
Defines the time in microseconds (millionths of a second) how long the device waits for the response from a Modbus slave. If the response is not received, the device can generate and return a Modbus gateway exception. The reply timeout of the Modbus master must be greater than the gateway device timeout. Otherwise, the flow of request-reply communication is violated. The device does not accept a new request before the reply from the slave is received or the reply timeout is elapsed. The delays in network communication can vary especially in wireless networks. When the slaves are located on the network side, ping or another method should be used to estimate the delay packets spend on network. |
0...90 000 000 (0...90 seconds) |
| Inter-frame timeout |
Defines the idle time in microseconds (millionths of a second) that marks the end of Modbus frame in serial communication. If the value is zero, the device uses the standard 4 character time. The recommendation is to use a value as small as possible to speed up communication and increase the value if problems arise. Some PC programs can insert unexpected delays between serial characters. |
0...2 000 000 (0...2 seconds) |
|
Exceptions |
||
|
Generate gateway exceptions |
Defines if the device generates and returns a Modbus gateway exception message to the master if no valid reply is not received from the slave. If set to “Yes”, the generation of exceptions is enabled. This functionality is useful for debugging. |
No, Yes |
|
Pass gateway exceptions |
If set to “Yes”, gateway exception replies from the slave side are passed to the master. If set to “No”, the replies are filtered away. |
No, Yes |
|
Network server settings |
||
|
Server TCP/UDP - port |
Defines the TCP or UDP port that masters can form connections to. Default Modbus TCP/IP communication port is 502. If multiple Modbus gateways are running on same device (for both serial ports) the TCP/UDP communication ports must not be same. For example, ports 502 and 504 can be used. The network and the device's firewalls must enable TCP or UDP communication for that port. |
1...32500 |
|
Max. number of clients |
Defines how many network masters can be connected to the device simultaneously. The recommended value is at least 2 when using TCP communication. Otherwise if the device does not recognize a partially closed connection, forming new connections is not accepted by the device the time set in parameter “Connection idle timeout” is elapsed. |
0...20 |
|
Connection idle timeout |
If there has not been communication on this route during given amount of seconds, the device automatically closes the TCP connection to slave and therefore frees the slave’s communication resources. This is especially useful when multiple masters access the same slave. The recommended setting is about two times the polling interval of the master. |
0...32500 |
|
Enable keepalive |
Defines if connection testing is performed by sending TCP keepalive packets at certain intervals. enabled for TCP network communication. If set to “Yes”, testing the TCP connection with slave is enabled. |
No, Yes |