Specific Time to energize an output

[Logan1101]

Wanting to know if you could set a Mitsubishi Fx PLC to energize an output and/or coil at a specific time?

Looking to automatically start a process when 5am hits. 

Edited September 28, 2021 by Logan1101

[Inntele]

And at what time to off? What serie of FX PLC? 

[Logan1101]

Looking to set a latch at 5am every morning to start a process Fx3u.

Edited September 28, 2021 by Logan1101

[Inntele]

!! In this case an output/coil wil be activated just once (at 5am) after running and never be deactived until the PLC will be gone into Stop mode or unpowered...

[BobLfoot]

1 hour ago, Logan1101 said:

Wanting to know if you could set a Mitsubishi Fx PLC to energize an output and/or coil at a specific time?

Looking to automatically start a process when 5am hits. 

So you're looking at 5am for an output coil to turn on and and stay on for five seconds or so to give a Start Pulse to a process?

[AndreasW]

in general, the internal clock of the plc can be used for this purpose. the internal clock can be queried in the program via special registers
(depending on the plc type) and can be used to switch an output.

However, it must be taken into account that the internal clock of the plc usually does not run completely accurately over a longer
period of time and that it shows a deviation after some time. Ideally, the plc should be able to synchronize its clock, for example using a NTP server (network time protocol)
available in the network (if plc has ethernet), although not all FX CPUs support this.
also the summer/winter time changeover is mostly still to be considered, since this won't change automatically.

I think the main problem is therefore not so much to switch an output at a given time, but rather to have the clock of the plc accurate.

 

 

[Inntele]

16 minutes ago, AndreasW said:

как правило, для этой цели можно использовать внутренние часы ПЛК. внутренние часы могут быть запрошены в программе через специальные регистры
(в зависимости от типа ПЛК) и могут использоваться для переключения выхода.

Однако следует учитывать, что внутренние часы ПЛК обычно не работают полностью точно в течение длительного
периода времени и через некоторое время показывают отклонение. В идеале ПЛК должен иметь возможность синхронизировать свои часы, например, используя NTP-сервер (сетевой протокол времени),
доступный в сети (если ПЛК имеет Ethernet), хотя не все ЦП FX поддерживают это.
Кроме того, переход на летнее / зимнее время по большей части еще предстоит рассмотреть, поскольку он не изменится автоматически.

Я думаю, что основная проблема заключается не столько в том, чтобы переключить выход в заданное время, сколько в том, чтобы часы ПЛК были точными.

 

 

Andeas W, this is about agrocultural automation. In this application the RTC accuracy is an evil) 

[Inntele]

Okey.
How is just to activate. For example:
 

LD= D8015 K5
AND= D8014 K0
SET M0

 

[AndreasW]

you can compare the data register or use the tcmp function

M0 is an internal relay, not an output. Outputs are Y___ eg. Y1
If you SET M or Y it will stay on and doesn't get reset. Either you add a RST command to
reset the relay/output or you can use a self-holding of the output using an timer
e.g. T0 is a 100ms Timer, so T0 K10 means 1second

e.g

check which outputs and timers you can use so that they do not collide with the existing PLC program

 

 

 

[Ron_S]

Use a digital time clock instead. The FX internal time is very poor without a way of correcting it regularly.

[Logan1101]

On 9/28/2021 at 2:39 PM, Inntele said:

!! In this case an output/coil wil be activated just once (at 5am) after running and never be deactived until the PLC will be gone into Stop mode or unpowered...

Yea because there is definitely not a way to reset a latch. 

[Inntele]

3 hours ago, Logan1101 said:

Yea because there is definitely not a way to reset a latch. 

Hmm, it sounds a bit strange. The way is present always.
Could you, pls, to describe your task in detail and I (we) will try to help you.