Allen-Bradley micrologix 1500, Руководство пользователя

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1 Publication 1764-UM001A-US-P
Chapter
6
Using Real-Time Clock and Memory Modules
Five modules with different levels of functionality are available for use with the
MicroLogix 1500 controller.
Real-Time Clock
Operation Removal/Insertion Under Power
The real-time clock module can be installed or removed at any time without risk of
damage to either the module or the controller. If a module is installed while the
MicroLogix 1500 is in an executing mode (Run or Remote Run), the module is not
recognized until either a power cycle occurs, or until the controller is placed in a
non-executing mode (program mode or fault condition).
Removal of the memory module is detected within one program scan. Removal of
the real-time clock under power causes the controller to write zeros to the (RTC)
Function File.
Real-Time Clock Function File
The real-time clock provides year, month, day of month, day of week, hour,
minute, and second information to the Real-Time Clock (RTC) Function File in
the controller. Refer to the
MicroLogix 1200 and MicroLogix 1500 Instruction Set
Reference Manual , publication 1762-RM001B-US-P for information about the
RTC function file.
Accuracy
The following table indicates the expected accuracy of the real-time clock at various
temperatures.
Catalog Number Function Memory Size
1764-RTC Real-Time Clock not applicable
1764-MM1 Memory Module 8K
1764-MM2 Memory Module 16K
1764-MM1RTC Memory Module and Real-Time Clock 8K
1764-MM2RTC Memory Module and Real-Time Clock 16K
Ambient Temperature
Accuracy
(1)
(1) These numbers are expected worst case values over a 31 day month.
0°C (+32°F) +34 to -70 seconds/month
+25°C (+77°F) +36 to -68 seconds/month
+40°C (+104°F) +29 to -75 seconds/month
+55°C (+131°F) -133 to -237 seconds/month
AB Spares