Справочник Пользователя для Mitsubishi Electronics FX
FX Series Programmable Controllers
Assigning System Devices 9
9-7
9.4
Real Time Clock Function
When one of the real time clock (RTC) memory cassettes is used with either and FX or an
FX0N, the real time clock function of that PLC is then automatically enabled.
The time data of the RTC cassette is battery backed. This means when the PLC is turned OFF
the time data and settings are not lost or corrupted. The duration or storage life of the time data
is dependent upon the condition of the battery. The operation of the RTC clock circuits
consumes negligible currents compared with the RAM memory (applicable to FX only).
The real time clock cassettes have a worst case accuracy of ± 45 seconds per month at an
ambient temperature of 25
FX0N, the real time clock function of that PLC is then automatically enabled.
The time data of the RTC cassette is battery backed. This means when the PLC is turned OFF
the time data and settings are not lost or corrupted. The duration or storage life of the time data
is dependent upon the condition of the battery. The operation of the RTC clock circuits
consumes negligible currents compared with the RAM memory (applicable to FX only).
The real time clock cassettes have a worst case accuracy of ± 45 seconds per month at an
ambient temperature of 25
°
C. The calendar function of the RTC cassettes caters for leap
years during the period 1980 through 2079.
FX PLC’s Pre Version 2.0
•
These PLC’s do not support the RTC function.
Available RTC Cassettes:
Function Registers And Control Flags:
•
Please see page 6-3 for a list of the available clock devices.
•
Please see section 5.14 (page 5-138) for RTC supporting functions with FX2N.
General Use Of Memory Cassettes
•
FX and FX
2C
Main Processing units can use any of the available memory cassette types.
FX
0N
units can only use EEPROM or EPROM type Memory Cassettes and then only a
maximum of 2k steps can be accessed.
•
It is necessary to install a FX
0N
-40BL battery to maintain the RTC time with FX
0N
controllers.
•
The FX
2N
has a real time clock built in to the MPU. Although it is possible to use the RTC
cassettes for memory, it is not necessary to use them to obtain the RTC function.
RTC Cassette
Remark
FX-RTC
Real time clock function only
FX-RAM-8C
Real time clock function + 8K RAM
(Note: the FX
0N
cannot use this cassette,
because RAM program storage is not guaranteed)
FX-EEPROM-4C
Real time clock function + 4K EEPROM
(Note the FX
0N
can only use 2K of the EEPROM)
FX
0(S)
FX
0N
FX FX
(2C)
FX
2N(C)