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About mohssen

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  1. Dear Professionals, I am new in AB PLC, but I know Siemens PLCs. I must learn AB and I appreciate any help regarding below basic questions: 1) What is the OS (Firmware) in AB PLC? Is there any OS commands concerning AB programming? 2)How does AB PLC execute the program in the cpu? ( in Siemens PLC, there are OB( organization Blocks) to write logic program and OB1 executes cyclically and therefore, any block which  is called in OB1 is executed by the cpu cyclically as well. Can we compare it to AB?) 3)How is the structure inside AB CPU concerning the RAM (different areas in the RAM for user program and OS etc), Micro-Processor, Memory Card etc 4)How AB PLC reads/writes IOs from the I/O modules? is there any Image area in the RAM for digital IOs ? how about analog IOs? As I am very new in AB programming, some of above questions may look silly, but any guide is highly appreciated. I need to start from somewhere :) Thanks     
  2. I love to know more about AB PLCs :-)

  3. Hi there, Ibelieve JRoss is right about switching from AB to Siemens. Actually, It won't worth to change all the Hardware and software of your control system just because of some difficulties you are facing with Modbus and EIP communication. I am well familiar with Siemens control systems and I can say Siemens has better performance in many aspects than AB, However, if you have an stablished control system, just keep going with it and find solution for it. Thinking of changing everything should have been made before designing the control system! By the way, there is a very small cheap and tiny module which can convert EIP to Modbus (TCP or RTU). It is very efficient for connecting your AB to a Modbus network. Please check GW-7472 module in bellow feel free to put your point of view here for us to talk more about AB and Siemens Good Luck
  4. c++ and plc

    Hi, It seems LS PLC ( diiferent types) has only Serial ports (RS-232 or RS-485). For this reason, you need to consider the serial communication. If you are going to Modbus, then Modbus RTU can be used with your PLC. However you may need a USB converter to connect it to your PC/Laptop. for this reason you may use RS-485 to USB converter like I-7561 If you are going to use Modbus TCP which is Modbus over Ethernet, you probaly will need MTCP to Serial converter as well. If so, you can use I-7188E3 Good Luck
  5. Modbus TCP to HIMA system

    It seems HIMA HIMAX is using Safe Ethernet. There are some overhead layers for safety. It may not be compatible with MTCP which just use normal Ethernet. You may need to convert the Safe Ethernet to Ethernet. This could be reason, however, if you clarify what sort of errors or trouble you are facing, we may better assist you.
  6. using usb adapter with QJ71C24 card

    Hi Kaare_t Thank you for your note. I admit you are right. I checked the converter and USB driver is required for PLC and it is difficult to install USB driver in a PLC.
  7. Siemens and Modbus TCP

    Hi Bryll, S7 can talk Modbus TCP as a client. You can see below examples: However, you can use Profibus to Modbus converters. Below are two converters you can use: Good Luck :)
  8. using usb adapter with QJ71C24 card

    Hi Firefinder, Normally, a USB to RS-232 converter should work for your device. Because both USB and RS-232 are standard communication protocols and a standard converter should be able to convert the data package and physical medium without any problem. I think you should double check the COM port settings in your new card configuration. make sure that the USB-to-Serial COM Port is assigned correctly. There are many other settings that must be the same for the port and the device being communicated with. Typically the manual for the device being connected will outline the correct settings, like baudrate, parity, stop bits etc. I suggest you to try with another standard USB-to-Serial converter as well and see if you can communicate or not. for example you can use below converter which works properly with different products and modules: The other issue which could be a reason for your communication problem, could be a special wiring for your serial device. you need to check its manual for pin assignment of its serial connector port. If so, you can use a converter with a terminal which allows you to wire your serial device directly to the converter terminal according your desire like below converter: hope it works for you Good Luck :)
  9. SLC500 5/03 with Ethernet

    Most AB PLC's can talk a variety of protocols natively (eg, DH, DHII, DH+, DF1, ASCII, DH-485, RIO, Devicenet, ControlNet, Ethernet/IP, Ethernet etc..) and through the use of encompass partners talk a variety of other languages (e.g. Modbus, Profibus, Fieldbus, Hart, etc...) through simple plug-in modules. There are also many gateway boxes made by AB and other 3rd party manufactures that will interface or bridge these networks together. You may take a look into converter table at below link: Good Luck :)
  10. PLC compatible for interfacing

    For converting Profinet to RS-232/RS-485 which is the physical layer in Modbus RTU, You may use I-7580:
  11. Hi, As you have two different brands, the best protocol to communicate is Modbus. Both brands can support it with their own communication cards OR you can also use an adapter for anyone of them to convert Modbus to any other protocol. For example,As most Siemens PLC has Profibus port on its CPU, you can use a Profibus to Modbus converter. you can select converters for many different protocols according below table:
  12. The most common of IO types are NPN, PNP, dry contact, 4-20 mA or voltage outputs. Once you know this and that you can accurately “see” your product or “measure” your product with your sensor. You may find many different type of Remote I/O modules based on different protocols ( like Modbus, Ethernet, Profibus, CAN bus, etc) and different I/O type Sink/Source Wet/Dry etc at below link: And also see below link which is very useful to select what you want: you may also use below table: (For sensors with NPN, PNP or dry contact outputs, use this table and select the module with the correct number of sensor inputs (or greater) and the matching output style:
  13. If the built-in RS-232 channel on your SLC 5/05 PLC is free, you can use a converter: RS-485 to RS-232. you can use I-7520 module: http://www.icpdas-us...r.html?r=mohsen Good luck!
  14. Modbus RTU over UDP/IP

    Modbus UDP is similar to simple Modbus serial protocol. it runs on top of a TCP/IP connection and has some bytes header at the beginning of each simple modbus frame, where frame means either a request or response packet. Modbus UDP protocol is nearly identical to Modbus TCP except that it runs connectionless on UDP/IP. Unlike TCP which is a gauranteed delivery service, when using UDP the application layer is responsible for any retries required due to possible loss of frames. For connecting your Device to ControlLogix5000, you can use a Modbus RTU to EtherNet/IP converter. for example you may use GW-7472 or GW-7473 below links: If you just need Modbus TCP, then you can convert your device Modbus RTU to TCP. for example you can use tGW-712: Good Luck!
  15. Hi Nizam, don't need to have a bridge( Micrologix 1400) as an interface to connect your EtherNet/IP to Yologawa DCS ( Modbus RTU). It is easire and cheaper to use just an adapter (EIP to Modbus RTU ). Such a gateway is very helpful for data-exchanging between the Modbus RTU network and the EtherNet/IP network. It reads the register data from the Modbus RTU Master (Yokogawa DCS) and publishes these data to the input register data of the EtherNet/IP scanner. You only need to consider Maximum EtherNet/IP Input/Output data size of such an adapter. I can refer you to GW-7473 which has : 200 bytes data size: Or GW-7473 which has 500 bytes: Good Luck