Sunday, July 22, 2012

FO Cable Port and Connector Types

Various different types of connectors are used for terminating the Fibers of Fiber-Optic (FO) cables. 

Here is a description of various standard Port / Connector types which are commonly used for terminating the FO cables. :

1. BFOC (ST ) Connectors
BFOC ( Bayonet Fiber Optic Connectors ) - Polularly known as ST ( Stick & Twist ) connectors are used for many devices e.g. Profibus Optical Link Modules OLMs and SCALANCE X100 and X200 series of switches.
Fig-1 - BFOC (ST) - Socket & Connector

2. SC Connectors

SC connectors are standard connectors for fiber optic cables. The SC connector is usually found in the duplex version, but can be used as a simplex connector by disconnecting it from the separator bar.  

Fig-2 - SC  - Socket & Connector
3. SC RJ Connectors

SC RJ45 is the smallest SC duplex plug-in connector. These are used in many new devices.
The overall size of the Sockets is about the same size as Ethernet RJ45 Ports. These are commonly used in devices with replacable / selectable ports.

Fig-2 - SC (RJ45) - Socket & Connector

4. LC Connectors

 LC connectors are highly compact "small form factor" (SFF) connectors of the new generation. The connector is available as a duplex version and is locked by the push/pull mechanism. They are used above all for connecting to SFP plug-in transceivers.

Fig-2 - LC - Socket & Connector


Different Types of Fiber Optic cables

The following fiber optic cables are available for Industrial Ethernet:
  • Glass fiber optic cable
  • PCF FO (Polymer Cladded Fiber)
  • POF FO (Polymer Optical Fiber)
The following fiber optic cables are available for PROFIBUS:
  • Glass fiber optic cable
  • PCF FO (Polymer Cladded Fiber)
  • Plastic FO
The table below gives you an overview of the connectors for connecting the above-mentioned fiber optic cables to the optical connections of the network components and terminals.

How to access a Password Protected S7-200 CPU

 !! Important Note !!  
It is always recommended to keep a copy of the program available on a data medium.
Moreover, the comments of the program are only available in the Offline-Project and are not loaded into the CPU.
There is NO possibility for the user, to read a program of a password-protected CPU with protection level 3 or to modify its program - without having the knowledge about the password.

Even if the CPU is furnished with a password protection, the followung  CPUFunctions can be executed  without any limitation :
  •  Start, Stopp and Restart of the CPU 
  • - Reading and setting the real-time

If the password entered in the CPU is unknown, a memory reset of the CPU has to be conducted and the program has to be reloaded into the CPU. During the memory reset, the net address, baudrate, realtime and - if existing - the program in the memory submodule are not modified.
To Execute CPU Memory Reset, please proceed as follows:
  • Select "Target system > memory reset".
  • Afterwards, select all three block types to be cleared and confirm it with "OK".

Fig. 1: Selecting blocks to be cleared
  • Enter "CLEARPLC" in the dialog window.
Fig. 2: Entry of the password in order to clear

  1. An additional possibility to reset the CPU is provided by the program "Wipeout.exe". This program is located on the Installation-CD of STEP7-Micro/WIN.
  2. On the contrary to the reset via STEP7-Micro/WIN, the program "Wipeout.exe" does not only delete the user program, the data block and the configuration information, but also the baudrate is reset to 9,6 kbit/s and the netaddress is reset to address 2. The CPU is reset into the pristine status of supply.
  3. Alternatively, the memory submodule can also be plugged with another unprotected program into the CPU. When reswitching the voltage, this program is loaded into the CPU and overwrites the program with the unknown password. Afterwards, the access to the CPU is possible.

Monday, July 16, 2012

How to Format or Reset an MMC (Micro Memory Card) for SIMATIC S7-300 CPUs?

!! Important Information !!
It is not possible for users to format a SIMATIC Micro Memory Card (MMC).
All you can do is "reset" an MMC, which deletes all user data.

!!! Caution !!!
Do not use the MMC for non-SIMATIC purposes and do not format it with a third-party device ( e.g. using a PC/Laptop MMC Reader. This would possibly overwrite the internal structure of the MMC that cannot be restored. In this case, the MMC is no longer recognized/accepted in a SIMATIC S7-300 CPU and can no longer be used with SIMATIC devices.

1. Resetting a MMC Card using a S7-300:

It is only possible to reset the MMC if it contains data that is invalid for the CPU ( for example, if the data stored is for a different type of CPU).  Otherwise the MMC is only initialized by the procedure described.
All the user data is deleted when you reset the SIMATIC Micro Memory Card (MMC). Proceed as follows.
  1. Power Off the S7-300 CPU and Insert the MMC into the MMC Slot.
  2. Power ON the CPU
  3. If the CPU displays slow blinking of the STOP LED then it is not able to read the MMC and is requesting an overall reset.
  4. Set the switch to "MRES" and hold it there until the STOP LED lights continuously (approx. 9 seconds).
  5. Within the next 3 seconds, you must let the switch go and set it again to "MRES". The STOP LED now blinks during the delete procedure.
If the CPU continues to request an overall reset after the procedure described above, then the MMC is defective.
2. Resetting a MMC Card using a PG/PC:

The SIMATIC Micro Memory Cards (MMCs) of the S7-300 may be read or written only by the following devices outside the CPU:
  • SIMATIC Field PG
  • SIMATIC Power PG
  • USB prommer (order number 6ES7792-0AA00-0XA0).
Using these devices, you can open an MMC in the SIMATIC

Fig-1 : How to Delete MMC Contents using a SIMATIC PG / USB Prommer