phatcreators
Member
How do we decide in programming a PLC that we use comparator, timer, registers, flags, function blocks etc for any task or for any network ?
thanks in advance
thanks in advance
first what you have to do decide
and second when there is any compression use compare,any time delay use timer TON,tof,rto based on application
do one thing go to the basic programming of plc pick some easy task and made it...
what is your plc and what is your application or only you want to learn plc.....specify then ask....
dear read this one...
http://www.plcs.net/contents.shtml
and tell me what type of plc do you want to work...or learn
i may be recommend you try Allen bradly first its very easy.....go to the AB website or some local vender they will provide you software then try this on that...you cant learn plc on air first you must have some software then the basic of plc and apply this one to you software in simulation way...
best of luck....
How do we decide in programming a PLC that we use (1)comparator, (2)timer, (3)registers, (4)flags, (5)function blocks etc for any task or for any network ?
thanks in advance
Use (1)compare instructions when you want to compare numerical data stored in (3)registers. The result of the comparison instructions is usually stored in single-bit (3)registers, called (4)flags. Compare instructions are instructions like (I have used the A-B mnemonics, the Siemens may be similar) ...
EQU equal
NEQ not equal
GRT greater than
LES less than
GEQ greater than or equal
LEQ less than or equal
Use (2)timer instructions to a) time an event, b) generate a time period (eg. a delay), c) generate a cyclic clock pulse, d) accumulate run hours for a piece of equipment.
Use (5)function blocks for other logic, eg PID control, program looping etc. There are many different (5)function blocks for a wide range of functions...
The terms have been thrown around loosely so that they have almost lost all true meaning. Downloading or uploading is relative to the system involved. It is like the theory of Relativity: time is only relative to the observer's viewpoint. Likewise, whether you are downloading or uploading depends on where you are standing, or on which computer you consider to be the observer's location.Some manufacturers view of Upload and Download is opposite : In the Allen-Bradley world, Download is to transfer the whole program to the PLC...
The terms have been thrown around loosely so that they have almost lost all true meaning. Downloading or uploading is relative to the system involved. ...........
Wikipedia said:Sideload
When applied to local transfers (sending data from one local system to another local system), it is often difficult to decide if it is an upload or download, as both source and destination are in the local control of the user. Technically if the user uses the receiving device to initiate the transfer then it would be a download and if they used the sending device to initiate it would be an upload. However, as most non-technical users tend to use the term download to refer to any data transfer, the term "sideload" is sometimes being used to cover all local to local transfers to end this confusion.