When would you use a bit address as B3:62/10, O:0.3/5, or I:4.1/2 instead of using the whole word such as B3:62, O:0.3, or I:4.1? Which is the correct method used for addressing actual outputs such as O:0.3 or O:0.3/5 "Turnstyle Rotate CW"? I am using RSLogix 500 for a SLC 5/03 and converting/rewriting a legacy 5TI program. Thank You
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Allen-Bradley PLC Programming & Addressing Question
- Thread starter mbd0722
- Start date
If the input / output / bit is digital, then address it down to bit level. If you have an array of bits, or an anlogue reading, then use the whole word, but for preference I'd use an N, not a B for a whole number, just so I know when I am looking at something if it is used elsewhere as an integer, or only as a single flag.
I think you can use either o:1.x or o:1/x to address down to bit level, but it's been a while since I used Bradley.
Any more questions, then feel free to ask, I can always dig out RSLogix and run up an old SLC if your struggling,
K
I think you can use either o:1.x or o:1/x to address down to bit level, but it's been a while since I used Bradley.
Any more questions, then feel free to ask, I can always dig out RSLogix and run up an old SLC if your struggling,
K
rayatucdavis
Technical User
The previous answer was correct regarding digital vs analog. By the way if you use an address like "B3:62/10 this is equivalent to the nine hundred and seventy second bit in the B3: file. Why not use separate "N" registers (i.e. N10,N20,N30...) for each element of your process.
The files stay smaller and you can more easily find bits/ words by equipment type this way.
- Thread starter
- #4
Thank you for your response Kalisto and rayatucdavis. I will use the N registers. I would like to pass messages, alarms, numerical data, and commands between an Allen-Bradley PanelView operator interface and a SLC5/03 controller. I have always worked at the bit level and not the word or file level so I am trying to understand the mechanics of passing words/files and then acting on specific bits. Any advice or direction for reference will be appreciated.
Thank You
mbd0722
Thank You
mbd0722
IIRC, you can specify down to word / bit level the N registers that you write to with a panelview.
If you solely use the N registers, I would have one for commands from the Panelview, and one or 2 to the panelview. (1 for animation / status updates, and a seperate one for the alarm handling).
But to complicate theings, theres no reason not to have 2 Bit files for binary data to / from the PV, and 2 N files for analoge data.
It depends on your personal preference, company standards, which way the wind is blowing etc
I'll mark the thread, so if you get stuck / want to pick my brains or shout at me for bad advice, I'll be here !
K
If you solely use the N registers, I would have one for commands from the Panelview, and one or 2 to the panelview. (1 for animation / status updates, and a seperate one for the alarm handling).
But to complicate theings, theres no reason not to have 2 Bit files for binary data to / from the PV, and 2 N files for analoge data.
It depends on your personal preference, company standards, which way the wind is blowing etc
I'll mark the thread, so if you get stuck / want to pick my brains or shout at me for bad advice, I'll be here !
K
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