Siemens SIMATIC NET S7-300-PROFIBUS CP 342-5 Technical Document

CP 342-5
SIMATIC NET
S7-300 - PROFIBUS
CP 342
-5
Equipment Manual
Manual Part B
01/2023
C79000
-G8976-C146-11
Preface
Application and functions
1
LEDs and mode selector
2
Installation, wiring,
commissioning, removal
3
Configuration and
operation
4
Diagnostics and upkeep
5
Technical specifications
6
Certifications and
approvals
A
References
B

Siemens AG
Digital Industries
Postfach 48 48
90026 NÜRNBERG
GERMANY
C79000-G8976-C146-11
Ⓟ
01/2023 Subject to change
Copyright © Siemens AG 2010 - 2023.
All rights reserved
Legal information
Warning notice system
This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent
damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert
symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are
graded according to the degree of danger.
DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
indicates that death or severe personal injury may result if proper precautions are not taken.
CAUTION
indicates that minor personal injury can result if proper precautions are not taken.
NOTICE
indicates that property damage can result if proper precautions are not taken.
If more than one degree of danger is present, the warning notice representing the highest degree of danger will
be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to
property damage.
Qualified Personnel
The product/system described in this documentation may be operated only by personnel qualified for the specific
task in accordance with the relevant documentation, in particular its warning notices and safety instructions.
Qualified personnel are those who, based on their training and experience, are capable of identifying risks and
avoiding potential hazards when working with these products/systems.
Proper use of Siemens products
Note the following:
WARNING
Siemens products may only be used for the applications described in the catalog and in the relevant technical
documentation. If products and components from other manufacturers are used, these must be recommended
or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and
maintenance are required to ensure that the products operate safely and without any problems. The permissible
ambient conditions must be complied with. The information in the relevant documentation must be observed.
Trademarks
All names identified by ® are registered trademarks of Siemens AG. The remaining trademarks in this publication
may be trademarks whose use by third parties for their own purposes could violate the rights of the owner.
Disclaimer of Liability
We have reviewed the contents of this publication to ensure consistency with the hardware and software
described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the
information in this publication is reviewed regularly and any necessary corrections are included in subsequent
editions.

CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 3
Preface
①
9-pin D-sub female connector
②
Status and error displays
③
Mode selector
④
Connector for power supply and functional ground
Validity of this manual
This manual contains information on the following products:
•CP 342−5
Article number: 6GK7 342-5DA03-0XE0
Hardware version: 2
Firmware version: V6.0.66
Communications processor for connection of SIMATIC S7-300 / to PROFIBUS DP

Preface
CP 342-5
4Equipment Manual, 01/2023, C79000-G8976-C146-11
Product name
•CP
In this document, the term "CP" is also used instead of the full product name of the two
modules.
Structure of the documentation
The documentation for this device consists of the following parts:
•Manual Part A - Configuration manual "Configuring and Commissioning S7 CPs for
PROFIBUS"
You will find this manual on the Manual DVD that ships with every CP or on the Internet at
the following address:
Link: (https://support.industry.siemens.com/cs/ww/de/view/1158693)
•Manual Part B - Manual "S7 CPs for PROFIBUS CP 342-5" (this manual)
New in this edition
•New approvals (CCC / UKEX)
•Editorial revision
Replaced documentation
This manual replaces the manual edition 07/2017.
Current manual edition on the Internet
You will also find the current version of this manual on the Internet pages of Siemens
Industry Online Support:
CP 342-5: (https://support.industry.siemens.com/cs/ww/en/ps/15674/man)
You can find the documentation for the discontinued CP 342-5 FO here:
CP 342-5 FO: (https://support.industry.siemens.com/cs/ww/en/ps/15675/man)

Preface
CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 5
License conditions
Note
Open source software
- CP 342-5
Read the license conditions for open source software carefully be
fore using the product. The
acceptance of the disclaimers of liability and warranty it contains is a clear precondition of
the use of open source software.
You will find license conditions in the document "OSS_CP3425_86.pdf" on the data medium
supplied wit
h the product documentation and on the Internet pages of Siemens Industry
Online Support.
FAQs on the Internet
You will find detailed information (FAQs) on using the PROFIBUS S7-CPs at the following
Internet address (entry type: FAQ):
Link: (https://support.industry.siemens.com/cs/ww/en/ps/15673/faq)
Note on firmware/software support
Check regularly for new firmware/software versions or security updates and apply them. After
the release of a new version, previous versions are no longer supported and are not
maintained.
Security information
Siemens provides products and solutions with industrial security functions that support the
secure operation of plants, systems, machines and networks.
In order to protect plants, systems, machines and networks against cyber threats, it is
necessary to implement – and continuously maintain – a holistic, state-of-the-art industrial
security concept. Siemens’ products and solutions constitute one element of such a concept.
Customers are responsible for preventing unauthorized access to their plants, systems,
machines and networks. Such systems, machines and components should only be connected
to an enterprise network or the internet if and to the extent such a connection is necessary
and only when appropriate security measures (e.g. firewalls and/or network segmentation)
are in place.
For additional information on industrial security measures that may be implemented, please
visit
Link: (http://www.siemens.com/industrialsecurity)
Siemens’ products and solutions undergo continuous development to make them more
secure. Siemens strongly recommends that product updates are applied as soon as they are
available and that the latest product versions are used. Use of product versions that are no
longer supported, and failure to apply the latest updates may increase customers’ exposure to
cyber threats.

Preface
CP 342-5
6Equipment Manual, 01/2023, C79000-G8976-C146-11
To stay informed about product updates, subscribe to the Siemens Industrial Security RSS
Feed under
Link: (https://www.siemens.com/cert)
Observe the following security recommendations to prevent unauthorized access to the
system.
•Evaluate your plant as a whole in terms of security. Use a cell protection concept with
suitable products.
•Keep the firmware up to date. Check regularly for security updates of the firmware and
use them.
•Restrict physical access to the device to qualified personnel.
•Configure a protection level of the CPU.
Recycling and disposal
The product is low in pollutants, can be recycled and meets the requirements of the WEEE
directive 2012/19/EU "Waste Electrical and Electronic Equipment".
Do not dispose of the product at public disposal sites. For environmentally friendly recycling
and the disposal of your old device contact a certified disposal company for electronic scrap
or your Siemens contact.
Keep to the local regulations.
You will find information on returning the product on the Internet pages of Siemens Industry
Online Support:
Link: (https://support.industry.siemens.com/cs/ww/en/view/109479891)
SIMATIC NET glossary
The SIMATIC NET glossary describes terms that may be used in this document.
You will find the SIMATIC NET glossary in the Siemens Industry Online Support at the
following address:
Link: (https://support.industry.siemens.com/cs/ww/en/view/50305045)
Training, Service & Support
You will find information on Training, Service & Support in the multi--language document
"DC_support_99.pdf" on the data medium supplied with the documentation.

CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 7
Table of contents
Preface ................................................................................................................................................... 3
1 Application and functions ..................................................................................................................... 9
1.1 Application .......................................................................................................................... 9
1.2 Interfaces and connectors.................................................................................................... 9
1.3 Communications services................................................................................................... 10
1.4 Performance data and behavior in operation ...................................................................... 11
1.4.1 Transmission speeds supported.......................................................................................... 11
1.4.2 Characteristic data of the DP interface / DP master.............................................................. 11
1.4.3 Characteristic data of the DP interface / DP slave................................................................. 13
1.4.4 Characteristic data of open communications services (SEND/RECEIVE interface) over
FDL connections ................................................................................................................ 15
1.4.5 Characteristics of S7 communication.................................................................................. 16
1.4.6 Characteristic data for multiplexing OP connections ........................................................... 17
1.4.7 Parallel use of communications services (multiprotocol mode) ........................................... 18
1.5 Requirements for use......................................................................................................... 19
1.5.1 Operation in control device families ................................................................................... 19
1.5.2 Project engineering............................................................................................................ 20
1.5.3 Program blocks .................................................................................................................. 21
1.6 Compatibility with the previous product............................................................................. 22
1.6.1 Enhanced functions and modifications............................................................................... 22
1.6.2 Replacing older modules / module replacement.................................................................. 23
1.6.3 Compatibility in the user program in DP mode.................................................................... 24
2 LEDs and mode selector....................................................................................................................... 29
2.1 LED displays....................................................................................................................... 29
2.2 Mode selector.................................................................................................................... 31
3 Installation, wiring, commissioning, removal ..................................................................................... 33
3.1 Important notes on using the device .................................................................................. 33
3.1.1 Notes on use in hazardous areas ........................................................................................ 33
3.1.2 Notes on use in hazardous areas according to ATEX / UKEX / IECEx / CCC-Ex ........................ 33
3.1.3 Notes on use in hazardous areas according to UL HazLoc and FM........................................ 34
3.2 Installation, removal and repairs in hazardous areas........................................................... 35
3.3 Installing, connecting and commissioning.......................................................................... 36
3.4 Disassembly....................................................................................................................... 38
4 Configuration and operation............................................................................................................... 39
4.1 Configuring in third-party systems ..................................................................................... 39
4.2 Loading with modified transmission speed......................................................................... 39
4.3 DP mode............................................................................................................................ 39

Table of contents
CP 342-5
8Equipment Manual, 01/2023, C79000-G8976-C146-11
4.4 Interface in the user program (status of blocks).................................................................. 40
5 Diagnostics and upkeep ...................................................................................................................... 41
5.1 Loading firmware .............................................................................................................. 41
6 Technical specifications....................................................................................................................... 45
A Certifications and approvals................................................................................................................ 47
B References ........................................................................................................................................... 53
B.1 On configuring and using the CP........................................................................................ 53
B.1.1 /1/ ..................................................................................................................................... 53
B.2 On installing and commissioning the CP............................................................................. 54
B.2.1 /2/ ..................................................................................................................................... 54
B.2.2 /3/ ..................................................................................................................................... 54
B.3 On programming............................................................................................................... 54
B.3.1 /4/ ..................................................................................................................................... 54
B.3.2 /5/ ..................................................................................................................................... 54
Index.................................................................................................................................................... 55

CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 9
Application and functions
1
1.1 Application
Automation system
The CP communications processor is intended for operation in a SIMATIC S7-300 / C7-300
automation system. It allows connection of the S7-300 / C7-300 to a PROFIBUS fieldbus
system.
1.2 Interfaces and connectors
The connectors are located behind the cover of the housing of the CP.
Connection to PROFIBUS
•CP 342-5
The interface is a 9-pin D-sub female connector operating according to the RS485
standard.
For information on the connection see section Installing, connecting and commissioning
(Page 36).
Connection to power supply
A 4-pin terminal is available for the 24 VDC power supply,
For information on the connection see section Installing, connecting and commissioning
(Page 36).

Application and functions
1.3 Communications services
CP 342-5
10 Equipment Manual, 01/2023, C79000-G8976-C146-11
1.3 Communications services
Supported communications services
In its current configuration, the CP supports the following communications services:
•PROFIBUS DP
–as DP master class 1 (PROFIBUS DP according to EN 50170 DPV0, DP master)
–as DP slave (PROFIBUS DP according to EN 50170 DPV0, DP slave)
Note
DP master or DP slave
Please note, however: The CP only supports operation either as DP master or DP slave.
You can also deselect DP mode altogether.
•S7 communication and PG/OP communication
–PG functions with uploading / downloading of FM modules, configuration / diagnostics
and routing
–Operator control and monitoring functions (HMI)
Multiplexing TD/OP connections
When multiplexing OP connections, the following acyclic services are supported:
- read once
- write once
- read system status list
–Client and server for data exchange via communication blocks on S7 connections
configured at both ends
The following blocks/functions are available:
BSEND FB 12, BRCV FB 13,
PUT FB 14, GET FB 15
USEND FB 8, URCV FB 9
C_CNTRL FC 62
You will find a more detailed description in /5/ (Page 54).
Note
The partner station can be an S7
-300, S7-400 or PG/PC application with SIMATIC NET
OPC server; raw data tags using BSEND/BRECV to WinCC are not supported.
–Server for data exchange on connections configured at both ends without
communications blocks on the S7-300 / C7-300 station

Application and functions
1.4 Performance data and behavior in operation
CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 11
•Open communications services (SEND/RECEIVE interface) over FDL connections of the
following type:
–Specified FDL connections
–Free layer 2 connections (SDA, SDN)
–Broadcast
–Multicast
The services of the CP listed above can be used independently at the same time.
1.4 Performance data and behavior in operation
1.4.1 Transmission speeds supported
The transmission speed is set with the SIMATIC STEP 7 configuration software. For permitted
values, refer to Technical specifications (Page 45).
Note
Remember the cable length
The permitted cable length must be kept to depending on the transmission speed. Refer to
the information in
/3/ (Page 54).
1.4.2 Characteristic data of the DP interface / DP master
General characteristic data
When operating the CP as a DP master, the following characteristic data is significant:
Characteristic
Explanation / values
Number of operable DP slaves
124 max.
Total number of operable slots
1024 max.
Size of the DP data areas (total):
•DP input area
•DP output area
2160 bytes max.
2160 bytes max.
Size of the DP data areas (per DP slave):
•DP input area
•DP output area
244 bytes max.
244 bytes max.
Size of the DP diagnostics data:
240 bytes per DP slave
PROFIBUS address range for DP master mode
1 - 125

Application and functions
1.4 Performance data and behavior in operation
CP 342-5
12 Equipment Manual, 01/2023, C79000-G8976-C146-11
Note
Optimum token passing
You can achieve optimum token passing by taking the following measures:
•
Assign the lower PROFIBUS addresses to the active nodes.
•
In the "Highest PROFIBUS address" input box, enter the highest PROFIBUS address of an
active node.
Note
Possible lack of resources with extensive configuration and parameter assignment data
The maximum number of connectable DP s
laves as shown in the table can be reduced if the
DP slaves require extensive configuration and parameter assignment data.
In this case, the configuration memory on the CP is not adequate. You will receive a message
in the diagnostics buffer of the CP indi
cating a lack of resources when you load the
configuration data.
Enhanced DP master functions
As DP master, the CP supports:
•SYNC/FREEZE (acyclic)
•Shared input/output (acyclic)
•Enable / disable DP slaves
•Settings that can be changed at run time:
–own PROFIBUS address
–DP operating mode (no DP, DP master, DP slave active/passive)
•Hardware interrupts / diagnostics interrupts
Hardware and diagnostics interrupts do not need to be evaluated in the user program.
Hardware and diagnostics interrupts are acknowledged automatically by the CP.
You can use single diagnostics to obtain interrupt information.

Application and functions
1.4 Performance data and behavior in operation
CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 13
Execution times of the program blocks for PROFIBUS DP
The following table will help you to calculate the CPU cycle times (OB1) in DP master mode.
The table contains the execution time of the program blocks (DP_SEND, DP_RECV) required
for DP processing on the S7-300 / C7-300 CPU.
Component
Explanation / guideline values
Execution time on the CPU
314C-2DP (6ES7 314-6CF00-
0AB0)
Per DP_Send block call:
•<3.0 ms at 8 bytes
•<5.0 ms at 2160 bytes 1)
Per DP_RECV block call:
•<3.3 ms at 8 bytes
•<5.8 ms at 2160 bytes 1)
Execution time on the CPU 317-
2PN/DP (6ES7 317-2EJ10-0AB0) Per DP_SEND block call:
•<1.5 ms at 8 bytes
•<2.3 ms at 2160 bytes 1)
Per DP_RECV block call:
•<1.7 ms at 8 bytes
•<2.8 ms at 2160 bytes 1)
1) the following applies at data lengths > 240 bytes: The data is transferred segmented over several
block calls.
Note
Time values are guidelines
The times shown for DP master mode should only be considered as guideline values. The
values apply only for
a mono master configuration when no other services (for example PG
functions) are processed on the CP.
Note
DP master mode and S7 slaves (ET
-200)
You will find important information on using and configuring (importing the GSD file) S7
slaves (ET200) when operating the CP as DP master on the Internet under the following entry
ID:
Link: (https://support.industry.siemens.com/cs/ww/en/view/21628502)
1.4.3 Characteristic data of the DP interface / DP slave
General characteristic data
The following characteristic data is important for successful data transfer from the DP master
to the DP slave:
Characteristic
Explanation / values
Generic station
description (GSD)
Depending on the CP type, use the following GSD files:
CP 342-5 (6GK7 342-5DA02-0XE0)
SIEM80D6.GSD
CP 342-5 (6GK7 342-5DA03-0XE0)
SI0180D6.GSD

Application and functions
1.4 Performance data and behavior in operation
CP 342-5
14 Equipment Manual, 01/2023, C79000-G8976-C146-11
Characteristic
Explanation / values
You will find GSD files on the Internet at the following address:
Link: (https://support.industry.siemens.com/cs/ww/en/view/113652)
Size of the DP data
areas
DP input area
240 bytes max.
DP output area
240 bytes max.
Min. slave interval
0.6 ms
SYNC / FREEZE
CP 342-5 (6GK7 342-5DA03-0XE0)
Is supported
User parameter assignment data
3 bytes; value: 40 00 00 (fixed)
User diagnostics data
0 bytes
Note
Fail
-safe
Fail-safe mode is possible only if you use the GSD files listed in the table above.
Execution times of the program blocks for PROFIBUS DP
The following table will help you to calculate the CPU cycle times (OB1) in DP slave mode. The
table contains the execution time of the FCs (FC DP_SEND, FC DP_RECV) required for DP
processing on the S7-300 / C7-300 CPU.
Component
Explanation / values
Execution time on the CPU
314C-2DP (6ES7 314-6CF00-
0AB0)
Per DP_SEND block call:
•<3.0 ms at 8 bytes
•<5.0 ms at 240 bytes
Per DP_RECV block call:
•<3.3 ms at 8 bytes
•<5.8 ms at 240 bytes
Execution time on the CPU 317-
2PN/DP (6ES7 317-2EJ10-0AB0)
Per DP_SEND block call:
•<1.5 ms at 8 bytes
•<2.3 ms at 240 bytes
Per DP_RECV block call:
•<1.7 ms at 8 bytes
•<2.8 ms at 240 bytes
Note
Time values are guidelines
The times shown for DP slave mode should only be considered as guideline values. The values
apply only when no other services (for example PG functions) are processed on the CP.

Application and functions
1.4 Performance data and behavior in operation
CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 15
1.4.4 Characteristic data of open communications services (SEND/RECEIVE
interface) over FDL connections
General characteristic data
The characteristic data is important when operating FDL connections (specified, free layer 2
(SDA and SDN), broadcast, multicast):
Characteristic
Explanation / values
Total number of FDL connections that can be
operated.
16 max.
Size of the transferable data area on FDL
connections. 1-240 bytes maximum per specified FDL connection (for sending and receiving):
Free Layer 2, broadcast and multicast:
Up to 236 bytes of user data can be transferred
per job. The job header occupies an additional 4
bytes.
Execution times of the program blocks AG_SEND / AG_RECV
The following table will help you to calculate the CPU cycle times (OB1) for FDL connections.
The table contains the execution time of the FCs (FC AG_SEND, FC AG_RECV) required for DP
processing on the S7-300 / C7-300 CPU.
Component
Explanation / values
Execution time on the CPU
314C-2DP (6ES7 314-6CF00-
0AB0)
Per AG_SEND block call:
•<5.1 ms at <=240 bytes
Per AG_RECV block call:
•<5.7 ms at <=240 bytes
Execution time on the CPU 317-
2PN/DP (6ES7 317-2EJ10-0AB0)
Per AG_SEND block call:
•<2.4 ms at <=240 bytes
Per AG_RECV block call:
•<2.8 ms at <=240 bytes
Time response on FDL connections
Refer to the following table for transmission rates with FDL connections dependent on the
following parameters:
•Frame length (number of bytes)
•CPU type
The values were measured while sending or receiving successively (at a transmission rate of
1.5 Mbps; bus profile standard; 9 nodes).
Table 1- 1 Number of FDL frames per second for CPU 317
Frame length
Number of FDL frames per second
8 bytes
140 / s
128 bytes
138 / s
240 bytes
135 / s

Application and functions
1.4 Performance data and behavior in operation
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16 Equipment Manual, 01/2023, C79000-G8976-C146-11
1.4.5 Characteristics of S7 communication
General characteristic data
The following information is important when operating S7 connections:
Characteristic
Explanation / values
Number of operable S7 connections
16 maximum
S7 connections configured at one end / both
ends; including PG and TD/OP connections
Dependencies and restrictions relating to the number of S7 connections
Depending on the configuration and modes, remember the following:
•The actual possible number of S7 connections that can be operated depends on the type
of CPU being used. Further restrictions result from multiprotocol mode; note the
information in the section Parallel use of communications services (multiprotocol mode)
(Page 18)
•If the CP is configured as a DP slave, the following restrictions apply:
–S7 connections cannot be operated;
–OP multiplex mode is not possible.
Execution times for program blocks for S7 connections
The following table will help you to calculate the CPU cycle times (OB1) for S7 connections.
The table contains the execution time of the program blocks (PUT, GET, USEND, URCV,
BSEND, BRCV) required for DP processing on the S7-300 / C7-300 CPU.
Execution time on the CPU per block call
Block type
PUT
GET
USEND
URCV
BSEND
BRCV
Data length
<=160 bytes
<=16 K bytes
CPU 314C-2DP
(6ES7 314-
6CF00-0AB0)
<5.6 ms
<5.8 ms
<6.0 ms
<5.6 ms
<5.7 ms
<5.8 ms
CPU 317-
2PN/DP (6ES7
317-2EJ10-
0AB0)
<2.1 ms
<2.5 ms
<2.0 ms
<2.4 ms
<2.1 ms
<2.7 ms
Time response on S7 connections
Refer to the following table for transmission rates with S7 connections dependent on the
following parameters:
•Frame length (number of bytes)
•Job type
•CPU type

Application and functions
1.4 Performance data and behavior in operation
CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 17
The values were measured while sending or receiving successively (at a transmission rate of
1.5 Mbps; bus profile standard; 9 nodes).
Table 1- 2 Number of S7 frames per second for CPU 317
Request type Frame length Number of S7 frames per
second
PUT
<=160 bytes
29 / s
GET
<=160 bytes
26 / s
USEND/URCV
<=160 bytes
35 / s
BSEND/BRCV
<=160 bytes
25 / s
<=400 bytes
14 / s
<=800 bytes
8 / s
1.4.6 Characteristic data for multiplexing OP connections
General characteristic data
The following information is important when operating HMI (TD/OP) connections:
Characteristic
Explanation / values
Number of operable HMI connections
16 max.
When multiplexing OP connections, the following acyclic services are supported:
•read once
•write once
•read system status list
If cyclic services or ProAgent interfacing (ALARM_S message block) are required, please
continue to use the rack/slot addressing of the remote S7-300 CPU.
Note
PG connections and connections to WinCC
PG connections and connections to WinCC are not operated over the multiplexer. When
operating a PG, a connection resource is always occupied.

Application and functions
1.4 Performance data and behavior in operation
CP 342-5
18 Equipment Manual, 01/2023, C79000-G8976-C146-11
1.4.7 Parallel use of communications services (multiprotocol mode)
Speed
Using the various available communications services at the same time affects the
communication speed.
Note
Recommendation for multiprotocol mode
In multiprotocol mode
- DP + FDL + S7 functions / TD/OP connections - you should select a
del
ay time of 2-5 ms.
Overall operational limits
When using communications connections/services at the same time, it is not possible to
achieve the maximum values as when using the communications connections/services alone.
Note the following limits:
Characteristic
Explanation / values
Number of operable connections in total:
•in operation with PROFIBUS DP
(DP master with up to 15 DP slave 1))
44 maximum
Of these, up to 16 FDL connections and 12 S7
connections and 16 OP connections in multiplex
mode.
•in operation without PROFIBUS DP
48 maximum
1) The number of S7 connections that can be operated when using the module as DP master depends
on the number and configuration of the assigned DP slaves (see table below).
Influence of the data length in S7 communication
In S7 communication, the data length of the jobs and in DP mode, the number of DP slaves
and the length of the I/O data mean the following restrictions:
•Number of S7 connections
•Number of jobs that can be sent at one time
The decisive factor is the job with the highest data length.

Application and functions
1.5 Requirements for use
CP 342-5
Equipment Manual, 01/2023, C79000-G8976-C146-11 19
The information in the following table applies to S7 job types BSEND/BRCV, PUT/GET, and
USEND/URCV.
Data length in bytes
1)
Number of S7 connections or number of S7 jobs
S7 communication
only
With DP master and 32
DP slaves ET200B
(1 byte I data and 1
byte Q data)
With DP master and 32
DP slaves ET200M
(32 byte I data and 32
byte Q data)
<=1000
16
10
8
2000
16
8
6
4000
16
6
5
8000
8
4
4
16000
4
2
2
32000
2
1
1
1) A maximum of 32 Kbytes can be transmitted with one BSEND/BRCV block, with
PUT/GET/USEND/URCV a maximum of 160 bytes in each case.
1.5 Requirements for use
1.5.1 Operation in control device families
SIMATIC device families
You can operate the CP in the following device families:
•SIMATIC S7-300 stations with the following CPU types:
–Standard
–Compact
–Modular
•SIMATIC C7 compact units in C7 packaging system
•SINUMERIK

Application and functions
1.5 Requirements for use
CP 342-5
20 Equipment Manual, 01/2023, C79000-G8976-C146-11
1.5.2 Project engineering
Configuration and downloading the configuration data
It is possible to download the configuration data to the CP via MPI or PROFIBUS. The following
version of STEP 7 is required:
STEP 7 version
Functions of the CP
STEP 7 as of V5.1
The functional range of the following CP type can
be configured:
•6GK7342-5DA02-0XE0
•STEP 7 as of V5.4.5 with Hotfix 4 and HSP
1049
•STEP 7 as of V5.5.2
•STEP 7 Professional V11 or higher
The functional range of the following CP type can
be configured:
•6GK7342-5DA03-0XE0
Depending on what is available on your PG / PC and the S7-300 station, use one of the following
connectors to load the configuration data: MPI, Industrial Ethernet or PROFIBUS.
Note
Changing bus parameters
If you change the bus parameters in the configuration data, you must not load this
configuration data on the CP via PROFIBUS!
Note
Extensive configuration
Before
loading an extensive configuration over a previous configuration, you should run a
memory reset on the CP.
By doing this, you avoid the configuration storage space on the CP being exceeded. If the
configuration storage space on the CP is not adequate, the
diagnostics buffer of the CP
reports a lack of resources when you download the configuration data.
Replacing a module without a programming device
The CP supports the option of storing the configuration data of the CP on the CPU. If you use
this option, this means that module replacement is possible without having to load the
configuration data from the PG again.
The configuration data is then stored in load memory of the CPU. Storage of the
configuration data is protected from power failure by the battery backup or the EPROM
module card in the CPU.