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Industrial Ethernet S7-300/400 CPs -- Configuring and programming communication -- Using communication blocks
How do you use the predefined data type UDT1 "FILE_DB_HEADER" for FTP communication in the S7-300 and S7-400?
How do you enable the ad-hoc mode when you call the TRCV instruction?
How do you use the blocks for MODBUS/TCP communication over an Industrial Ethernet CP of S7-300 and S7-400 in STEP 7 Professional (TIA Portal)?
How do you copy the CFC chart "Modbus" from the sample project for OPEN MODBUS / TCP into your user project?
What is the difference between the initialization and runtime parameters on the blocks for Modbus TCP?
Why is the status value A090 (hex) output for Modbus TCP although you have entered the correct license?
What are the differences between the licensed version and the downloadable demo version of the blocks for Modbus TCP?
Why is the value A083 (hex) output permanently at the STATUS output parameter of the block for Modbus TCP when the ENQ_ENR=true input parameter has been set?
How is data with variable message length transferred via the TCP protocol and received by an S7-300 station via the Industrial Ethernet CP?
How do you program the function blocks FB14 "GET" and FB15 "PUT" in the S7 program of the S7-300 in order to transfer more than 160 bytes of data?
Where can you find sample programs and documentation for communication from SIMATIC S5 modules to SIMATIC S7 modules via Industrial Ethernet using the UDP protocol?
Where can you find sample programs and documentation for communication from SIMATIC S5 modules to SIMATIC S7 modules via Industrial Ethernet using the TCP protocol?
Where can you find sample programs and documentation for communication from SIMATIC S5 modules to SIMATIC S7 modules via Industrial Ethernet using the ISO transport protocol?
How do you program the FC10 "AG_CNTRL"?
Which commands (CMD) of the FC10 "AG_CNTRL" are supported by the IE CPs?
How many communication jobs may be used simultaneously in an S7-300 CPU for S7 communication via a CP343-1?
Which ports are released for Modbus/TCP communication and how many Modbus clients can communicate with a SIMATIC S7 CPU as Modbus server?
Notes on using an instance for multiple connection IDs
Internal call of FC5 (AG_SEND) with FTP client blocks (FC 40-44) for the CP343-1 IT (6GK7 343-1GX11-0XE0)
How do you program the communication blocks FB63 "TSEND", FB64 "TRECV", FB65 "TCON" and FB66 "TDISCON" in order to use the ISO-on-TCP protocol for data exchange by way of the integrated PROFINET interface of a CPU or by way of the CP443-1 Advanced?
How do you program communication blocks FC11 and FC12 for the PROFINET IO device?
Block calls for communications processors in multiple runtime layers
Changing the input parameter of the user blocks "AG_SEND" and "AG_RECV" during the runtime of a job
What should you watch out for if you transfer variables with the data type "REAL" when calling the communication blocks FC5/50 "AG_SEND/AG_LSEND" and FC6/60 "AG_RCV/AG_LRCV"?
What should you pay attention to when using the communication blocks FC53 "AG_SSEND" and FC63 "AG_SRECV"?
What points do you need to remember when calling communication blocks FC5/50 and FC6/60 in the STEP 7 user program of the CPU?
How do you program communication blocks FC11 and FC12 for the PROFINET IO controller?
How do you establish OPEN MODBUS / TCP communication from a SIMATIC S7 and where can you find further information?
How do you program the communication blocks FC50 and FC60?
Error STATUS "0x7000" on function block FC6 / FC60 (AG_SEND) with Send/Receive communication on the S7-400 controller
How do you program the communication blocks FC5 and FC6?
Sample program: S7 communication with the blocks SFB14 ("GET") and SFB15 ("PUT") with S7-400
Sample Program: S7 Communication with blocks FB14 ("GET") und FB15 ("PUT") of the CPU 317-2PN/DP
How do you program communication blocks FB8 "USEND" and FB9 "URCV" for data exchange on the S7-300?
"STATUS = 27" (0x001B) with the loadable S7 communication on the S7-300
How do you program communication blocks FB14 "GET" and FB15 "PUT" for data exchange in the S7 program of an S7-300 CPU?
How do you program communication blocks FB12 "BSEND" and FB13 "BRCV" for data exchange in the S7 program of an S7-300 CPU?
Repeating the "BSEND" job (SFB12) when the "BRCV" block (SFB13) is in the "disabled" state ("EN_R = 0")
PROFIBUS S7-300/400 CPs -- Configuring and programming communication -- Using communication blocks
How do you program the communication blocks FC50 and FC60?
How do you program communication blocks FB12 "BSEND" and FB13 "BRCV" for data exchange in the S7 program of an S7-300 CPU?
How do you program communication blocks FB14 "GET" and FB15 "PUT" for data exchange in the S7 program of an S7-300 CPU?
Which blocks for Modbus TCP can you rename or re-wire when the block numbers of the Modbus blocks are already being used in the user program?
How do you program the function blocks FB14 "GET" and FB15 "PUT" in the S7 program of the S7-300 in order to transfer more than 160 bytes of data?
Where can you find sample programs and documentation for using the PROFIBUS DP protocol for data communication between SIMATIC S5 modules and SIMATIC S7 modules?
Where can you find sample programs and documentation for communication from SIMATIC S5 modules to SIMATIC S7 modules by way of PROFIBUS using the free Layer 2 of the FDL protocol?
Where can you find sample programs and documentation for communication from SIMATIC S5 modules to SIMATIC S7 modules by way of PROFIBUS using the FDL protocol?
Where can you find sample programs and documentation for using the PROFIBUS FMS protocol for data communication between SIMATIC S5 modules and SIMATIC S7 modules as well as for data communication between SIMATIC S5 modules and PCs?
Notes on using an instance for multiple connection IDs
Processing the data from DP slaves via CP342-5 on CPU31x
Block calls for communications processors in multiple runtime layers
Changing the input parameter of the user blocks "AG_SEND" and "AG_RECV" during the runtime of a job
What should you watch out for if you transfer variables with the data type "REAL" when calling the communication blocks FC5/50 "AG_SEND/AG_LSEND" and FC6/60 "AG_RCV/AG_LRCV"?
How do you program the communication blocks FC5 and FC6?
What properties and special features does S7 Basis Communication offer?
PROFIBUS: diagnostics of S7 connections with STEP 7
Repeating the "BSEND" job (SFB12) when the "BRCV" block (SFB13) is in the "disabled" state ("EN_R = 0")
How do you program communication blocks FB8 "USEND" and FB9 "URCV" for data exchange on the S7-300?
Particularities when assigning parameters of the communication blocks of CP 342 / CP 343
What should you watch out for when upgrading the CP 342-5 or fitting spare parts?
Which version of the function blocks do you need to operate a CP 342-5?
CP 342-5 -- How can you tell that the CP 342-5 has withdrawn from the PROFIBUS?
CP 342-5 -- How do you program data communications when your DP slave only has outputs?
CP 342-5 -- How can you read and write consistent data of a DP slave via the CP 342-5?
Notes on using an instance for multiple connection IDs
Part number:

QUESTION:
Why isn't it useful to realize BRCV or URCV with an instance via multiple communication connections?

ANSWER:
The communication services BSEND/BRCV and USEND/URCV are bilateral communication functions that enter a 1:1 connection with each other. This is why a BSEND is always assigned to exactly one BRCV via one S7 connection. The S7 communication functions (SFBs) are realized on the S7-400 controllers in such a way that the input parameters ID and R_ID cannot be changed dynamically in the program, but always belong to one specific instance DB.

The dynamics of the downloadable communication functions for S7-300 controllers is different: an instance (DB) is fixed for only one communication task and then it can be used for another partner, i.e. S7 connection. This is practical in particular for the S7 functions PUT/GET in order to be able to address several partners with one instance.

This is more complicated for the S7 functions BSEND/BRCV and USEND/URCV. Here you could implement dynamic use of the instance DBs for the Send blocks BSEND/USEND. However, this is not possible on the Receive side, because you cannot foresee exactly which S7 Communication would like to send.

This applies also for parallel communication functions for an S7 connection that are realized with the parameter R_ID (task reference). There is no point either in using a single instance in this variant of the S7 Communication.

Keywords:
Downloadable communication, URECEIVE, BRECEIVE,
SFB8, FB8, SFB9, FB9, SFB12, FB12, SFB13, FB13, SFB14, FB14, SFB15, FB15


 Entry ID:11062167   Date:2003-09-09 
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