5/3/2011 10:32 AM | |
Joined: 1/28/2009 Last visit: 9/10/2024 Posts: 6849 Rating: (1365) |
I think the main reason behind this is the idea of Decentralization. There are several reasons mentioned here like easier mechanical installation, Reduced wiring and fast installation and commissioning. If you use central modules in the H configuration,this may need extra programming for redundancy purposes. I think you can easily find a module with the spec mentioned in S7 300 series' modules scope.Try decentralized configuration and its benifits. regards |
5/25/2011 2:14 PM | |
Joined: 9/6/2008 Last visit: 5/7/2022 Posts: 1121 Rating: (86) |
Hi What hdhosseini said is true, the S7400 cards are bigger and bulkier, the S7300 cards are compact and use to use in case of wiring in the panel, by using S7400 CPU and ET200M cards you can go for redudant architecture and expand your system to the max limit. It is advisable to take the combination of S7400 CPU/ S7 300 CPU along with ET200M cards so that you can have a distributed architecture. Have fun... |
Jazz |
|
5/29/2011 2:23 AM | |
Joined: 7/2/2008 Last visit: 9/25/2024 Posts: 928 Rating: (308)
|
Hello Everyone, Very interesting discussion. I just would like to drift the conversation a little to the main thread that's similar to this one.
With your eyes being closed, go for ET200M as long as isolation voltagehas not been mentioned in project requirements.
1st Sometimes oil & gas customers object to the isolation voltage of 500 VDCfor S7-300 analog modules butit's very rare. 2ndI don't think Siemens designed S7-400 I/O modules justfor the benefit of isolation. S7-400 is the evolution of S5-135U and S5-155U/H. So, S7-400 had to come with its own CPUs, its own function modulesand its ownI/O modules. Although you can useS7-300 modules with S7-400 CPU in a distributed architecture, this doesn't change the fact that S7-400 is acomplete familywithPSs,CPs,FMs and I/O modules. I must admit that it's very rare nowadays to see a control system built totally with S7-400 modules. Everybody prefers to unify the I/O modules in the whole factory/plant and use the S7-300 modules whether it's S7-300 CPU or S7-400 CPU. However, someOEMs still prefer to build their complex machines with S7-400, itsFMs and its I/O modules. ----------------------------------------------------------------------------------------------------------- Some differences between 400 and 300 modules: 1- You can have 16 modules of 32 channels in a singleS7-400 expansion rack while you are limited to 12 modules in ET200M. 2- S7-400family has an analog input module with 16 channels while S7-300 has a max. of 8 channels per module. 3- Now S7-300 family has a module with 64 inputs (but without front connector). 3- S7-300 (ET200M)modules have a big advantage which is the MTA (Marshalled Termination Assemblies) while S7-400 modules lack something similar. Finally Ithink that most of S7-400 modules are being used in migration projects as a direct replacement for S5-135U and S5-155U/H I/O modules speciallywith the benefits of S5 to S7 adapters. In the companyI work for we use S7-400 modules only for migration projects. ----------------------------------------------------------------------------------------------------------- My friend, are you sure?! I don't think so, I've done it before and I don't remember I've written something special. Anyhow, I do not recommend central redundant I/Os as long as it's possible to work with ET200M. Best regards. H-H |
This contribution was helpful to1 thankful Users |
5/31/2011 8:44 AM | |
Joined: 4/24/2009 Last visit: 8/20/2024 Posts: 2682 Rating: (135) |
Hello together, i just wanted to inform you that some posts of this discussion were splitted to the following new thread What do you think of using Y-Link and ET200S with 400H-CPU?. Best regards O_Moderator |
This contribution was helpful to1 thankful Users |
Follow us on