Hach-Lange SC 1000 Controller Enhanced Communications - Manual (Page 41)

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Section 4 Error messages
4.1 GSM/GPRS
See GSM error messages in the sc1000 controller manual.
There are no specific status messages for GPRS.
4.2 VPN tunnel
There are several status messages associated with establishing the VPN tunnel
connection. These are displayed under SYSTEM SETUP>BROWSER ACCESS>VPN:
• OFF: The OpenVPN client is deactivated
• LINK CONNECTION : The OpenVPN client is attempting to establish a connection to
the server.
• CONNECTION: A connection to the server has been established.
• INTERRUPTED: The connection to the server has been interrupted. This status is
displayed if the Internet connection is disrupted, e.g. the Ethernet cable is removed or
the GPRS connection is terminated. The connection is automatically established
again once the communication error has been resolved.
4.3 Modbus TCP
If an error occurs, the Modbus TCP server returns corresponding exception codes to the
querying client (
Table 4 ).
The last exception code returned to each connected client is displayed in the SYSTEM
SETUP>MODBUS TCP>STATUS menu.
SYSTEM SETUP
BROWSER ACCESS
VPN
SYSTEM SETUP
MODBUS TCP
STATUS
Table 4 Modbus exception codes in accordance with Modbus specification
Exception code Designation
01 Illegal Function
02 Illegal Data Address
03 Illegal Data Value
04 Illegal Response Length
05 Acknowledge
06 Slave Device Busy
07 Negative Acknowledge
08 Memory Parity Error
10 Gateway Path Unavailable
11 Gateway Target Device Failed to Respond