Specifications

Allen-Bradley DF1 Driver Help

Function File Options

Function files are structure-based files, similar to PD and MG data files, and are unique to the Micrologix 1200

and 1500. For more information on a specific function file are supported in the Allen-Bradley DF1 Device Driver,

select a link from the list below.

High Speed Counter File (HSC)

Real-Time Clock File (RTC)

Channel 0 Communication Status File (CS0)

Channel 1 Communication Status File (CS1)

I/O Module Status File (IOS)

Function File Block Writes

For applicable function files, data can be written to the device in a single operation. By default, when data is

written to a function file sub element (field within the function file structure), a write operation occurs

immediately for that tag. For such files as the RTC file, whose sub elements include hour (HR), minute (MIN) and

second (SEC), individual writes are not always acceptable. With such sub elements relying solely on time, values

must be written in one operation to avoid time elapsing between sub elements writes. For this reason, there is the

option to "block write" these sub elements.

Applicable Function Files/Sub Elements

RTC

Year YR

Month MON

Day DAY

Day of Week DOW

Hour HR

Minute MIN

Second SEC

How Block Writes Work

Block writing involves writing to the device the values of every Read/Write sub element in the function file in a

single write operation. It is not necessary to write to every sub element prior to performing a block write. Sub

elements not affected (written to) will have their current value written back to them. For example, if the current

(last read) date and time is 1/1/2001, 12:00.00, DOW = 3, and the hour is changed to 1 o'clock, then the values

written to the device would be 1/1/2001, 1:00.00, DOW = 3.

Instructions