Using The Wall Clock Time In Controllogix

In v16 and later this button not only sets the controller s clock to match the pc s date and time but also sets the controller s clock to match the pc s tz and dst settings.

Using the wall clock time in controllogix.

Needed something like this to transfer system time to an rsview register for an event time stamp. Yet another section would display the total number of seconds that have passed since jan 1 1970. Unlike the plc 5 slc 500 and micrologix all of which have a status file to access similar information in a controllogix or compactlogix requires a gsv get system variable or ssv set system variable instruction. 12 thoughts on reading the controllogix system time in ladder logic steve august 18 2010 at 10 43 pm.

Still struggling with defining the tag values and getting the proper response. Time synchronization is accomplished by using these methods standards and protocols. Controllogix control systems our controllogix control systems use a common control engine with a common development environment to provide high performance in an easy to use environment. The first step is to find out the current time which you can read from your processor using a gsv instruction.

All clocks ultimately derive their time from a clock known as the grandmaster clock. Furthermore the controllogix processor will not automatically adjust for daylight savings time. However many programmers began to enable the tz and dst settings inadvertently when using the set time button in controller properties. 1756 time module obtains time from various sources and provides time synchronization on other devices by acting as a gateway between different time synchronization methods and standards.

One section would display the current time in our own time zone. Gsv wallclocktime the register containing the microseconds is the 7th element in the array. Look at the date time tab in the controller properties window. These sections would be the attributes.

We set the clock forward one hour in the spring and back one hour in the fall. Imagine a large clock on the wall with different sections. The controllogix backplane for coordinated system time cst and. Another section attribute would be for utc.

This is where the clock update tool can come in handy. If you are using the ab controllogix platform and want a bit to cycle on and off at a consistent rate you can address one of the bits of the register that represents the clock microseconds. Once all the clocks in a control system share a synchronized common understanding of system time events being monitored in the control system for example the controllogix system can be time stamped to a very high degree of accuracy.