Nexto XF #76 – Adjusting the Real Time Clock of the XF

The purpose of this tutorial is to explain how to adjust the real-time clock of the XF via MasterTool X.

Components

Equipment: 1 computer/laptop.

Software:  MasterTool X

Tutorial Sections

1. ARCHITECTURE
2. DEVELOPMENT

1. ARCHITECTURE

A computer/laptop will be required to use MasterTool X.

Figure 1. Computer running MasterTool X

2. DEVELOPMENT

Access to the RTC (Real Time Clock) of the PLC is essential in applications that use time control, event logging, and process synchronization, allowing the user to check and adjust the controller’s date and time.

Prerequisites

To use this feature:

• The PLC must be connected to MasterTool
• The PLC must be in RUN mode (RAM)
• Does not work in simulation

Important:
Real-time variables are only updated with the physical equipment, as they depend on the CPU’s internal clock.

Accessing time variables (RTC)

To view the PLC’s date and time:

1. In the TreeView, go to:
   System GVLs → Special Variables
2. Locate the structure:
   SystemTime
3. Expand the structure

Available variables

Inside SystemTime, the user can view:

• Day of the month
• Month
• Year
• Hour
• Minutes
• Seconds

These variables show the current controller time.

RTC verification

The user can:

• Monitor these variables online
• Compare with the actual date and time
• Check if the PLC is properly synchronized

Figure 2. Accessing the PLC’s RTC variables

Clock adjustment (RTC)

If it is necessary to adjust the date and time:

1. Access the top menu Communication
2. Click on Clock configuration

Configuration options

In the configuration window, there are two ways to adjust:

Manual adjustment

• The user defines:
  • Date
  • Time

After entering:

1. Click Write to PLC

Automatic adjustment (via computer)

• The system uses the computer’s date and time

To apply:

1. Click Write to PLC

Figure 3. Adjusting the PLC’s RTC variables

Operation

After configuration:

• The PLC updates its internal clock
• The SystemTime variables reflect the new time

Automation applications

• Event logging (logs)
• Time-based control
• Supervisory systems
• Temporal sequences
• Process auditing