DamianInRochester
Lifetime Supporting Member
OP
STEP 7 and RSLogix5000
- Thread starter DamianInRochester
- Start date
KalleOlsen
Member
If you make an FC for the purpose, it could look like this, no IOs.
FC1, named IToR
ITD
DTR
In the code
L IntegerFromDrive
UC IToR
T HereIsTheValueInReal
(I usually put scaling into the block as well. And limits. And a lowpass. And limit violation timeouts. And a substitute value. And...)
Kalle
FC1, named IToR
ITD
DTR
In the code
L IntegerFromDrive
UC IToR
T HereIsTheValueInReal
(I usually put scaling into the block as well. And limits. And a lowpass. And limit violation timeouts. And a substitute value. And...)
Kalle
RSLOGIC 5000 can do all of that
This has reduced down to a S7 vs RS5k debate.
I like Unitronics.
The Datatables are 2 dimensional. AB has no DB or DT but they have open memory and a UDT could be seen as a DB or DT.
Step7 DBs are essentially an EXCEL spread sheet constrained to one column. Associating the Nth BYTE in one DB with the Nth BYTE in a second DB is not simple. This can be solved by using an array of UDT inside the DB. or of course a bunch of STL.
Unitronics DTs are native 2 dimensional. I suppose it is the same as an array of UDT, but it is easier to implement. The down side is not being able to use the memory in the DT without first moving it to a marker memory. DB12.DBW4 not possible in Unitronics. No chance for Symbolic addressing either.
DT xx, row [N] move to some memory area. Then use memory area in code. Easy to make code once that looks at a lot of different cases though. Sort of makes up for no FC.
Also Unitronics has a formula block, in which a complete math problem can be defined. Very nice.
Unitronics software is free.......free.........yes...........free.
Download cable is free..........yes free......and included one with every PLC.
The PLC has an HMI built in. Same software used for HMI and PLC. They are always integrated.
The cost is < 1k USD for most units.
The hardware has many communication options.
The hardware I/O can be expanded, but the upper limit is far lower than the big PLCs which makes Unitronics the solution for small projects only. Unless the solution can use many small PLCs with HMIs instead of one big PLC.
However, no FC, no FBs, no add on. But Uni does have subroutines.
And support is free, even though the company is very small.
And they have their own PLC forum.
GE could re-assign the actual hardware config so any output could be re-assigned to any output number. This was only an advantage once, when an output went out and I could reassign it in the hardware config which prevented editing the code.
AB (SLC 500) RS500 can set up the hardware config automatically, which I always enjoyed.
Step7 is more involved in the HC and in general Step 7 does NOTHING "automatically".
The help files and PDFs for Step7 are in sort of English which it is possible to knowing the correct response but then after some reading to get more confused than before the beginning.
AB has a very clear documentation with examples.
Why does it spark such a debate when auto type casting is discussed?????
Why can Step7 NOT do this ?
INT X REAL = MW4 then the answer is an INT
INT X REAL = MD4 then the answer is an INT.
DINT X REAL = MD4 then the answer is an DINT.
If I made the SFC for mixed math, I would output the same type as the first variable. Alternated, one could argue in favour of using an interface or maybe 2 different standard math blocks. One ouputs as real, the other as INT or DINT depending on the output assigned. Yes, don't tell me which data type I can use. Look and see which one I used, then cast the answer as that type!
I know this requires some processor and programming power. But we are using machines to do this.
rounded or truncated is the only debate I have here, could go with an interface for that or have it in a right click option menu for each instance.
I agree that anything can be done with any controller, but the way it is done will vary.
Also the best method to solve an issue will not be easily found by a person who is unfamiliar with the platform.
LD, you have highlighted the one true strength of Step7. The ability of Germans to write obtuse, undocumented code that no one has the patience to unravel. This to me is not a strength, but a serious flaw. Although if you want to make code that only you can support, Step 7 is your best choice.
Post a piece of code that is not deliberately opaque and this could be translated into any other PLC.
I have the most freedom in Step7, but then we all have maximum freedom in assembly code. Why don't we all program in assembly??????
CodeSYS allows several languages to be used inside the interface. One of which looks like C and makes PLC programming easy for the PC guys.
STL and SCL could be replaced by C++, but then it wouldn't be easy to read by the maintenance techs..............but then STL isn't easy to read by most people.
SCL wasn't included in the base Step7 before V5.5 or 5.4, I think it would be more widely used if it had been included and not separate. Of course SCL compiles to STL, and it always seems to compile to a enormous amount of STL.
So it's most likely no as fast.
Just some random thoughts.
Most PLCs will do most jobs. The programmer needs to take the time to explore the strengths of the platform to get the most out of the hardware.
It is obvious that a recent project I am working on, was written by AB guys using Step7. Very inefficient but it works.
I like Unitronics.
The Datatables are 2 dimensional. AB has no DB or DT but they have open memory and a UDT could be seen as a DB or DT.
Step7 DBs are essentially an EXCEL spread sheet constrained to one column. Associating the Nth BYTE in one DB with the Nth BYTE in a second DB is not simple. This can be solved by using an array of UDT inside the DB. or of course a bunch of STL.
Unitronics DTs are native 2 dimensional. I suppose it is the same as an array of UDT, but it is easier to implement. The down side is not being able to use the memory in the DT without first moving it to a marker memory. DB12.DBW4 not possible in Unitronics. No chance for Symbolic addressing either.
DT xx, row [N] move to some memory area. Then use memory area in code. Easy to make code once that looks at a lot of different cases though. Sort of makes up for no FC.
Also Unitronics has a formula block, in which a complete math problem can be defined. Very nice.
Unitronics software is free.......free.........yes...........free.
Download cable is free..........yes free......and included one with every PLC.
The PLC has an HMI built in. Same software used for HMI and PLC. They are always integrated.
The cost is < 1k USD for most units.
The hardware has many communication options.
The hardware I/O can be expanded, but the upper limit is far lower than the big PLCs which makes Unitronics the solution for small projects only. Unless the solution can use many small PLCs with HMIs instead of one big PLC.
However, no FC, no FBs, no add on. But Uni does have subroutines.
And support is free, even though the company is very small.
And they have their own PLC forum.
GE could re-assign the actual hardware config so any output could be re-assigned to any output number. This was only an advantage once, when an output went out and I could reassign it in the hardware config which prevented editing the code.
AB (SLC 500) RS500 can set up the hardware config automatically, which I always enjoyed.
Step7 is more involved in the HC and in general Step 7 does NOTHING "automatically".
The help files and PDFs for Step7 are in sort of English which it is possible to knowing the correct response but then after some reading to get more confused than before the beginning.
AB has a very clear documentation with examples.
Why does it spark such a debate when auto type casting is discussed?????
Why can Step7 NOT do this ?
INT X REAL = MW4 then the answer is an INT
INT X REAL = MD4 then the answer is an INT.
DINT X REAL = MD4 then the answer is an DINT.
If I made the SFC for mixed math, I would output the same type as the first variable. Alternated, one could argue in favour of using an interface or maybe 2 different standard math blocks. One ouputs as real, the other as INT or DINT depending on the output assigned. Yes, don't tell me which data type I can use. Look and see which one I used, then cast the answer as that type!
I know this requires some processor and programming power. But we are using machines to do this.
rounded or truncated is the only debate I have here, could go with an interface for that or have it in a right click option menu for each instance.
I agree that anything can be done with any controller, but the way it is done will vary.
Also the best method to solve an issue will not be easily found by a person who is unfamiliar with the platform.
LD, you have highlighted the one true strength of Step7. The ability of Germans to write obtuse, undocumented code that no one has the patience to unravel. This to me is not a strength, but a serious flaw. Although if you want to make code that only you can support, Step 7 is your best choice.
Post a piece of code that is not deliberately opaque and this could be translated into any other PLC.
I have the most freedom in Step7, but then we all have maximum freedom in assembly code. Why don't we all program in assembly??????
CodeSYS allows several languages to be used inside the interface. One of which looks like C and makes PLC programming easy for the PC guys.
STL and SCL could be replaced by C++, but then it wouldn't be easy to read by the maintenance techs..............but then STL isn't easy to read by most people.
SCL wasn't included in the base Step7 before V5.5 or 5.4, I think it would be more widely used if it had been included and not separate. Of course SCL compiles to STL, and it always seems to compile to a enormous amount of STL.
So it's most likely no as fast.
Just some random thoughts.
Most PLCs will do most jobs. The programmer needs to take the time to explore the strengths of the platform to get the most out of the hardware.
It is obvious that a recent project I am working on, was written by AB guys using Step7. Very inefficient but it works.
Siemens vs Rockwell
Hi all
I arrived here checking on internet the differences between Siemens and Rockwell systems.
I start to tell that I'm beginner in Rockwell and try to understanding for a next fast project, based on knowledge what I have regarding Siemens systems. I worked mostly with Siemens many years and I know pretty well. So I mention this, to understand one perspective from a guy who comes from Siemens to Rockwell without any major help.
As I see here and not only, many people is telling that Rockwell is more easy and I try to figure that.
I see that discusion is old but the problems seams are actually the same.
I try to update one project Rockwell v20.01 and I get a library in project v13.04. Already begin problems.
- in project example v13.04 I have a lot of UDT and I can't export directly in block (only one by one), in first hand. I understood that in Rockwell differences between versions are big problem (HW and SW). If you bild a project in a version you must us only in that. In Siemens a project build in a old version, I open it with v5.5 without any problem and work normally.
- the HW project is included in SW and my seams have new HW devices which my RSLogix5000 nor recognize. In Siemens I can separate HW by SW and work independent giving more flexibility, and usually I prefer that in commissioning. In Rockwell seams not.
- I try to figure how to update "easly" this new HW devices in Rockwell to indentfy itself what is new. I can't. In Siemens when I get a new project with a HW Config which include new GSD is updating automaticaly itself when I open it. More there in Siemens is a feature HW Update to update automaticaly all library. In Rockwell is not and can update only one by one, what you need, but you must know exactly what you search.
- in Rockwell I have ACD project and open it with these HW devices not recognized completly. I can export as L5K file without any error, but I can't import it back anymore!!!
- I try to make a Rockwell master project (same version 20.01) for what I have to import in site in other projects. People from office told me that should be most easy procedure exporting program and importing back should import all tags and UDT related. I export the program as L5X file and I can't import in any program (same version) not only what I need. In Siemens if I want to import tags, I just copy from symbolic file and paste in other (no mater what version) and no errors. If I want to export a function (or a group) just select and make AWL which can be imported in other project with compile. UDT impossible to export in block in Rockwell. In Siemens open a block go in meniu Options/Customize/Sources/Execute and select everything what you want and make AWL which can be imported very easy in other project.
- I try to compare two different blocks in Rockwell which I suspect are very similar and there not exist such option. Compare all project or nothing (not speaking even about online version)!!! In Siemens I compare very simple any block with anything from any other project (no need to have even same name) - online or other offline version.
- VAT tables not exist at all in Rockwell systems. For commissioning is a very usefull tool.
- moreover I understood when I will be in site, I must import some programs and in this way the tags and refreshed canceling whatever was before (in Rockwell). In Siemens updating a function or importing a new one which use same old tags is not updating anything in that tags.
- in Rockwell I saw that it's allow in some branch to bypass just straight (with a line) an instruction and the SW is giving just an warning!!! Siemens not permit this.
- in Rockwell I see also writing many outputs in same branch in AND logic, SW giving again just a warning. In Siemens is not allowed this.
These is what I see just until now.
I tell again this opinion is just from a guy coming from a system in other. For sure is the same coming from other side and don't know where to look. But here for me I asked about my Rockwell problems and I get incomplete answers. Should be ... Is like this but I don't know why not working ...
I think in this moment (2016), Rockwell have more problems then Siemens.
Hi all
I arrived here checking on internet the differences between Siemens and Rockwell systems.
I start to tell that I'm beginner in Rockwell and try to understanding for a next fast project, based on knowledge what I have regarding Siemens systems. I worked mostly with Siemens many years and I know pretty well. So I mention this, to understand one perspective from a guy who comes from Siemens to Rockwell without any major help.
As I see here and not only, many people is telling that Rockwell is more easy and I try to figure that.
I see that discusion is old but the problems seams are actually the same.
I try to update one project Rockwell v20.01 and I get a library in project v13.04. Already begin problems.
- in project example v13.04 I have a lot of UDT and I can't export directly in block (only one by one), in first hand. I understood that in Rockwell differences between versions are big problem (HW and SW). If you bild a project in a version you must us only in that. In Siemens a project build in a old version, I open it with v5.5 without any problem and work normally.
- the HW project is included in SW and my seams have new HW devices which my RSLogix5000 nor recognize. In Siemens I can separate HW by SW and work independent giving more flexibility, and usually I prefer that in commissioning. In Rockwell seams not.
- I try to figure how to update "easly" this new HW devices in Rockwell to indentfy itself what is new. I can't. In Siemens when I get a new project with a HW Config which include new GSD is updating automaticaly itself when I open it. More there in Siemens is a feature HW Update to update automaticaly all library. In Rockwell is not and can update only one by one, what you need, but you must know exactly what you search.
- in Rockwell I have ACD project and open it with these HW devices not recognized completly. I can export as L5K file without any error, but I can't import it back anymore!!!
- I try to make a Rockwell master project (same version 20.01) for what I have to import in site in other projects. People from office told me that should be most easy procedure exporting program and importing back should import all tags and UDT related. I export the program as L5X file and I can't import in any program (same version) not only what I need. In Siemens if I want to import tags, I just copy from symbolic file and paste in other (no mater what version) and no errors. If I want to export a function (or a group) just select and make AWL which can be imported in other project with compile. UDT impossible to export in block in Rockwell. In Siemens open a block go in meniu Options/Customize/Sources/Execute and select everything what you want and make AWL which can be imported very easy in other project.
- I try to compare two different blocks in Rockwell which I suspect are very similar and there not exist such option. Compare all project or nothing (not speaking even about online version)!!! In Siemens I compare very simple any block with anything from any other project (no need to have even same name) - online or other offline version.
- VAT tables not exist at all in Rockwell systems. For commissioning is a very usefull tool.
- moreover I understood when I will be in site, I must import some programs and in this way the tags and refreshed canceling whatever was before (in Rockwell). In Siemens updating a function or importing a new one which use same old tags is not updating anything in that tags.
- in Rockwell I saw that it's allow in some branch to bypass just straight (with a line) an instruction and the SW is giving just an warning!!! Siemens not permit this.
- in Rockwell I see also writing many outputs in same branch in AND logic, SW giving again just a warning. In Siemens is not allowed this.
These is what I see just until now.
I tell again this opinion is just from a guy coming from a system in other. For sure is the same coming from other side and don't know where to look. But here for me I asked about my Rockwell problems and I get incomplete answers. Should be ... Is like this but I don't know why not working ...
I think in this moment (2016), Rockwell have more problems then Siemens.
Last edited:
redbarron55
Member
This might be very applicable in my case.
I have to work with S7-200,300,400,and PCS7 and I find the Siemens systems confusing.
I can transition fairly easily to the RSLogix since I grew up with PLC5, but the Siemens leaves me wishing for something else.
Of course for the last 13 years I have been working with Modicon so I am not the best judge on this subject.
Typically I get involved with AB to pull the fat out of the fire for other of my companies sites and I do little original work with them.
However we will be starting up an AB project addition where I primarily work so I assume I will get more involved with is for at leas a few months.
Jnoobs
Member
98% of my time has been dealt with Siemens, using Simatic Manager and even Portal for the 1200 and 1500 processors. My current project is an AB, which is my first time using RS Studio 5000, and all i can say is "confused."
jstolaruk
Lifetime Supporting Member
98% of my time has been dealt with Siemens, using Simatic Manager and even Portal for the 1200 and 1500 processors. My current project is an AB, which is my first time using RS Studio 5000, and all i can say is "confused."
I was exposed in the opposite and was also confused with Step 7. IMHO there are more undocumented quirky things with Siemen's then RSlogix but Siemen's tech support has gotten leaps and bounds better than it was 10 years ago.
mokong1925
Member
Hi there.
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