My head hurts !

markymark31

Member
Join Date
Mar 2004
Location
Corby, Northants
Posts
60
Hi Guys,

Just getting back into programming after a long break !

Setup :
RSLogix 5000
FTView Studio ME
1769-L35E Processor
Pro-Soft MVI69PDPMV1 Profibus Module and a few other I/O cards etc.
Panelview Plus 1000 Compact

My question is this .......

The Pro-Soft card feeds I/O information into a controller tag that is made up as a SINT[1536].

There are two bytes of data within this tag
MVI69PDPMV1.Input[14] and
MVI69PDPMV1.Input[15] that are the speed that my motor is running at so I want to extract them and display them on my PVP.

Now I can point to each byte individually from the PVP but I need them combined as a 16 bit number to display the full speed value.

Ideally I also need this to work in the reverse direction so that I can enter a speed on my PVP and then write it to two other bytes which would set the motor speed.

I hope I have explained this okay, and hope that someone can help with this.

Many Thanks,

Mark
 
I would perform this function in the plc with a COPy command. It would look something like:

COP
Source: MVI69PDPMV1.Input[14]
Dest: ActualSpeed
Length: 1

where ActualSpeed is a controller level 16-bit integer.

To go the other way would be:

COP
Source: CommandedSpeed
Dest: MVI69PDPMV1.Output[14]
Length: 2

where CommandedSpeed is the speed setpoint as a controller level 16-bit integer.

The HMI would read ActualSpeed and write CommandedSpeed.

Keith
 
Thanks Keith that's excellent.

Just a couple of questions .....

Why length 1 then length 2 ?

The speed value can be a negative as it also sets the motor direction, does this confuse things ?

Mark.
 
The COP instruction copies however many bytes from the source element as are required to fill the destination element.

COP SINT INT 1 - Copies two bytes (SINT[0] & SINT[1]) to INT

COP SINT DINT 4 - Copies 4 bytes (SINT[0] - SINT[3]) to DINT

COP DINT SINT 1 - Copies the first byte of DINT to SINT

COP INT REAL 2 - Copies 4 bytes (two ints) from INT to REAL

COP INT SINT 2 - Copies both bytes from INT to SINT[0] and SINT[1]

COP INT SINT 1 - Copies only the first byte of INT to SINT[0]

As long as negatives are represented as two's complement, and the byte order is proper, this shouldn't be an issue, as it seems the input is just SINT type as a convenience, but actually can represent different values.
 
The COP instruction copies however many bytes from the source element as are required to fill the destination element.

COP SINT INT 1 - Copies two bytes (SINT[0] & SINT[1]) to INT

COP SINT DINT 4 - Copies 4 bytes (SINT[0] - SINT[3]) to DINT

COP DINT SINT 1 - Copies the first byte of DINT to SINT

COP INT REAL 2 - Copies 4 bytes (two ints) from INT to REAL

COP INT SINT 2 - Copies both bytes from INT to SINT[0] and SINT[1]

COP INT SINT 1 - Copies only the first byte of INT to SINT[0]

As long as negatives are represented as two's complement, and the byte order is proper, this shouldn't be an issue, as it seems the input is just SINT type as a convenience, but actually can represent different values.

Close, but not quite. The length is always determined in the units of the destination type.

COP SINT DINT 4 - Copies 4 bytes (SINT[0] - SINT[3]) to DINT
should be COP SINT DINT 1

COP INT REAL 2 - Copies 4 bytes (two ints) from INT to REAL
should be COP INT REAL 1
 
I have problems with comm between MVI69-PDPMV1 and slave UCM22-FBP (V.4.00) (BB_082D.GSD)
in this moment led APP is ON and MSTR STAT is RED.

Please help me

my layout is: six slave (address 2,3,4,5,6 y 7) and block 60 word.
 

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