Operating Hours Counter

Description

The operating hours counter can record the operating hours of a device accurately to the second. There are a total of three operating hours counters. In addition to an operating hours counter for the operating hours since the start of the device, there is a total operating hours counter and a customer-specific operating hours counter that can be reset. The storage interval is configurable and the operating hours are not stored once one million storage cycles have been reached.

The output of the operating hours can serve as a time control for the service interval as well as for preventative maintenance. Schedules for regular service can be tied to the operating hour values. Moreover, a high value of the total operating hours is indicative of intensive use of a device and possible deterioration of the performance. The risk of failure can be countered preventatively through replacement.

Algorithm

While the counter is incremented every second, the storage interval doubles after each save operation. Starting with a save operation after 1 minute, then after 2 minutes, then after 4 minutes, then after 8 minutes, up to a maximum storage rate of 12 minutes.

Process Data

Operating hours counter – Process data
Object ID	Name	Description	Direction
0x001B (27)	Current Operating Hours	Output of the current operating hours counter	Input
0x001C (28)	Total Operating Hours	Output of the total operating hours counter	Input
0x001D (29)	Custom Operating Hours	Output of a user-defined operating hours counter	Input

Also see Process Data Profiles.

ISDU

Operating hours counter – ISDU
Name	Index	Subindex	Access	Length	Data Type	Data Storage	Default
Operating Hours Counter	0x0057 (87)	0	R	12 bytes		n/a
Current Operating Hours		1	R	4 bytes	UINT32	n/a	–
Total Operating Hours		2	R	4 bytes	UINT32	n/a	–
Custom Operating Hours		3	R	4 bytes	UINT32	n/a	–
Operating Hours Saving Mode	0x0074 (116)	0	R/W	1 byte	UINT8 (ENUM)	Yes	0

Note

The maximum counter value that can be saved is 1,000,000 and, with a switch-on and switch-off every 12 minutes (with static counter), this means a service life of over 20 years.

If switched on and off more frequently or in the case of dynamic storage, the maximum storage time is reduced depending on the application.

Current Operating Hours Parameter

This parameter saves the value of the operating hours since the last commissioning in seconds.

Total Operating Hours Parameter

This parameter saves the value of the operating hours since the first commissioning in seconds.

Custom Operating Hours Parameter

This parameter saves the value of the operating hours since the last reset in seconds.

Operating Hours Saving Mode

The current storage behavior can be set.

Operating Hours Counter – Operating Hours Saving Mode
Value	Meaning	Description
0x00 (0)	Dynamic	The first save operation is performed 1 minute after switching on; the storage interval than doubles after every save operation. This is limited to a storage interval of 12 minutes. The intervals are 1, 2, 4, 8, 12 minutes.
0x01 (1)	Static	Operating hours counters are stored every 12 minutes.

System Commands

Operating hours counter – System Commands
Command Value	Device Action
0x81 (129)	Application Reset – Resets Custom Operating Hours to the default value.
0x82 (130)	Restore Factory Settings – Resets Custom Operating Hours and Operating Hours Saving Mode to the default value.
0xA5 (165)	Maintenance Reset – Resets Custom Operating Hours to the default value.