Proroute
GEM
2M
4G
Router
GEM-2M series User Manual
127
1. Operation Mode:
the definition of Modbus Gateway is an adapter application
enables conversions between Serial and Network Modbus protocols.
2. Serial Protocol:
defines the Modbus protocol used on the serial communication.
3. Listen Port:
defines the TCP or UDP port that Masters can make connections to.
4. Serial Response Timeout:
if the serial side does not response within the specific
time, data would be dropped and not transmitted over TCP even if the gateway
receives it later (if the response is not received, the gateway can generate and
return the Master exception)
5. Serial Timeout Retries:
If "0" is set, the gateway would not store TCP packets in
the buffer. If the number is greater than "0", the gateway would store the TCP
packets in the buffer and retries the specified time when the Modbus device on the
serial side does not response.
6. 0Bh Exception:
Modbus protocol defines that the 0Bh is “an error code which
means error message of the interconnected gateway, or no response of the
access device”. When the Modbus slave device does not respond before the
timeout has been reached or has a bad response (check sum does not match),
the 0Bh exception code is transmitted to the master that initiated the Modbus
message.
7. Serial Message Buffering:
if this option is selected, the gateway will buffer TCP
up to 32 requests. If this option is unselected, the gateway will respond with a 06h
if it has a message out on the port with no response yet.
8. Tx Delay:
this is the minimum amount of time after receiving a response before
the next message can be sent out.
9. TCP Connection Idle Timeout:
idle timeout in seconds for the Modbus /TCP
connection. If the gateway doesn't receive any Modbus /TCP query within the
specific time, the connection will be closed.
10.
Maximum TCP Connection:
maximum of four simultaneous Modbus /TCP
connections is allowed
11. TCP Keep-alive:
enable the connection testing enabled for TCP network
communication
12. Trusted IP Access:
defines the IP that is allowed to connect to the gateway
13.
Modbus Priority:
defines the priorities from specific IP, or Modbus ID or
