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MODBUS-GW Installation and Operation Manual —
P/N LS10015-000NF-E:C2 4/30/2019
Configuration
Security Certificate
3.3 Security Certificate
The MODBUS-GW communicates with the browser using secure communications facilitated by a self-signed security certificate. Using
the self-signed security certificate will cause the browser to display warnings similar to the following:
Figure 3.2 Chrome Security Warning Example
The browser warning is displayed upon each connection to the gateway. The warning may be removed by obtaining a security certificate
from a security authority.
The certificate may originate from a local certificate authority or a commercial certificate authority if the gate-
way is directly connected to the Internet with a unique IP address. Regardless of which type of certificate authority is selected, the IP
address of the gateway must be provided. The certificate is specific to the specified IP address. If the IP address is changed, a new certif-
icate will be required. In addition, the certificates have an expiration date. Once the certificate expires, a new certificate needs to be sent
to the gateway. If the certificate expires, a different warning is displayed by the browser.
The security certificate must be in the PFX format. The PFX file is uploaded to the gateway using the
Tools > Send PFX Key File
option in the gateway configuration tool. It may be necessary to install a file on each PC used to configure the gateway to fully resolve
the security configuration.
The MODBUS-GW includes a self-signed security certificate. The certificate is generated with a three year expiration. In addition, the
certificate is generated using the default IP address of the gateway, 192.168.1.2. A certificate authority may be used to create a valid cer-
tificate based on the IP address of the MODBUS-GW. If a certificate authority is not available, a local IT administrator may use a secu-
rity certificate generation application such as OpenSSL to generate the certificate.
The site network administrator may be able to assist with any additional details regarding security certificates.