GE Industrial Solutions Entellisys 4.0 System Administrator Manual - Manual (Page 19)

Modbus ® security 19
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• The Local and Master HMI controls are disabled
• Does not send out email notifications for alarms
• Does not have ability to block breaker commands
• Uses port 502 for Modbus TCP/IP communication with CPUs
• Does not update time and time zone bias information of the CPUs
Communication restrictions
The CPUs can support up to 8 simultaneous communication ports for Modbus clients. Once the
limit is exceeded, clients will be blocked until a port is free. The Local HMIs have special ports
reserved for its use.
To set an Local HMI as a “Master”
1. On the Main Menu, click the Maintenance button. The button will only be displayed if access
is allowed with the current login permissions.
2. Click the Modbus Security tab.
3. Select the Master check box as shown in Figure 4-5.
4. Click the OK button to save changes (or click Cancel to cancel changes).