Description
Below is a sample FM351 project using STEP 7 Professional V11 (TIA Portal) or higher.

zEn18_02_FMx51_Prog.zip ( 4617 KB )

Notes on the commissioning of the example are available

• In the FM351 manual in Entry ID 2103043.
• In the Getting Started in Entry ID 2029985.

Configuration Notes
This entry provides information about which function modules can be configured in an ET 200M remote IO system and which can then be operated remotely.

Below is a list of the function modules that can be configured and used behind the PROFIBUS interface modules of the ET 200M.
In the compatibility list a difference is made between configuration via the metaknowledge integrated in STEP 7 and GSD configuration.

21536617_Compatibility_FM_with_PROFIBUS_InterfaceModules_en.pdf ( 83 KB )

In the entry below is a list of the function modules that can be configured and used behind the PROFINET interface modules of the ET 200M: 45313498.

Note
The entry below provides you with more information about function modules which use the functions "Read data record" and "Write data record": 15364459.
The entry below provides more information about using a positioning module FM 357-2: 21385102.

Description (task)
In absolute value encoders, the "Set reference point" function is used to synchronize the absolute value encoder with the machine coordinate system. This enters the reference point coordinate and the absolute value encoder adjustment online into the FM's machine data. However, this machine data is overwritten by transfer of the system data blocks the next time the CPU is restarted. The absolute value encoder adjustment from the user program should likewise also be retained upon restart of the CPU or FM.

Validity
This FAQ describes how to perform encoder adjustment without a PG/PC and thus without parameterization interface.
The solution described here is only relevant for using absolute value encoders on the FM and is valid for:

• FM 351
• FM 352
• FM 451
• FM 452

Setting the reference point and retaining the machine data

More information on this is available in the following manuals:

• FM 351, sections 9.6 and 8.1, in Entry ID: 2103043
• FM 451, section 9.8, in Entry ID: 2126468
• FM 352, sections 10.4 and 9.3, in Entry ID: 2103044
• FM 452, sections 10.4 and 9.3, in Entry ID: 1123332

Now the current machine data and the FM's encoder adjustment are located in the CPU's parameter DB and will be retained there.

Loading machine data and encoder adjustment after CPU startup

More information on this is available in the following manuals:

• FM 351, section 8.1, in Entry ID: 2103043
• FM 352, section 9.2, in Entry ID: 2103044
• FM 452, section 9.2, in Entry ID: 1123332

Now the machine data and the encoder adjustment are stored again in the FM.

Applications for "Change cam flanks" and "Fast cam change"
You can also apply this procedure if through the "Change cam flanks" function (FM 352 manual, section 10.5, in Entry ID: 2103044) or the "Fast cam change" function (FM 352 manual, section 10.6, in Entry ID: 2103044) the cam data has been changed online on the FM and is to be active again after the next restart. For this, after a change in the parameter DB, the cam data has to be read and also written after CPU startup (FM 352 manual, section 9.1, in Entry ID: 2103044).

QUESTION:
How do I use the FM351 to measure the actual value?

ANSWER:  
Incremental encoder and absolute encoder can be connected to the FM351. Both can be used to measure the actual value.

Requirements: 

• The machine has to be taken into operation in order to enable the proceeding movements;
• The FM351 has to be configured.

Parameter assignment:
Switch off the monitoring for the standstill range.
In the configuration software of the FM351, the monitoring for the standstill range has to be switched off. The parameter "Standstill range" will be set to ZERO in in the configuration dialog box "Drive".

The following steps will lead you to the configuration dialog box "Drive"

• Double-click on the FM351 in the HW-Config -> Double-click on "Drive"

After any parameter changes a download has to be executed to the respective channel of the FM351. ("Target system" ->" load channel "-> choose concerned channel)



Fig. 1: Configuration dialog box "Drive"

Move the mechanisms for the adjustments of the absolute encoder: 

• Move the axis to a reproducible position. Assign the desired coordinate value to this position.
  Enter this coordinate value in the machine data as a reference point coordinate.
• Read the sensor actual value displayed at this point  from the service mask of the configuration software. Entert this value as an absolute encoder adjustment into the machine data.

At the use of an absolute encoder these steps only have to be executed once, e.g. during the commissioning. 

All opened parameter windows have to be saved and closed after successful absolute encoder adjustment. Execute then the "Save and Compile" in the hardware configuration and load the HW-Config into the CPU.

At the use of an incremental encoder a synchronisation has to be built up with the mechanic, after each start of the controller. To do so execute the job "Set bench mark".

User program:

The actual value of the sensor can be read in the user program on the following periphery address:

• Sensor actual value of channel 1 = Starting address of the FM351 out of the HW-Config. + 4
• Sensor actual value of channel 2 = Starting address of the FM351 out of the HW-Config. + 12

Example:
the address of the FM351 in the HW-Config. is 256

• Sensor actual value of channel 1 = 256 + 4
• Sensor actual value of channel 1= 260 à the access in the user program is L PED 260
  
  
• Sensor, actual value of channel 2 = 256 + 12
• Sensor, actual value of channel 2 = 268 à the access in the user program is L PED 268

Further information about this topic can be found in the manual "Positioning module FM 351 V5.x", Issue 03.00, Entry-ID 2103043: 

Absolute encoder adjustment	Chapter 8.6
Set bench mark	Chapter 9.6

QUESTION:
Which address areas are possible for FM351 with CPU WinLC?

ANSWER:
The active mode of user surface of FM351 is substituted with "not assigned" after pressing drive enable ON/OFF and start enable will be reset (Fig. 1), only if you run FM 351 over PROFIBUS DP with a WINLC Basis 4.0 and the hardware address of the FM 351 is outside the process image.

Fig. 1: Commisioning Mask of FM351

Remedy:
Change the size of the process-image input / output areas in "Properties of WinLC > Cycle/Clock Memory" of hardware configuration such that the hardware address of FM is within this area (Fig. 2).

Fig. 2: Process Image Parametrization in Hardware Configuration

Note:
As of WinLC V4.0 + SP1 you can place the hardware address of the FM351 outside the process image.