S7-300 CPU 31xC 和 CPU 31x

Routing and data record routing

Routing is the transmission of data across network boundaries. Information can be sent from sender to receiver across several networks.

The data logging route is an extension of the common route. For example, when the programming device is not directly connected to the target device

PROFIBUS DP subnets, but when connected to the CPU's PROFINET interface, SIMATIC PDM will make

Record routes with data. The data sent through the data recording route includes parameters of the participating field devices (slave stations)

Configuration, and device-specific information (e.g., set values, limit values, etc.). Data records the destination address structure of the route

Depends on the content of the data, i.e. the secondary station receiving the data.

When a programming device is assigned a different subnet from the target slave station, the data record route can also be read using the programming device

Set of parameters that already exist on the field device, edit them, and return them to the field device.

The field devices themselves do not need to support data record routing because they do not forward the received information.

Clock synchronization

1:intro

The CPU interface supports clock synchronization. The CPU can be programmed to act as a time master (with a default synchronization interval)

Interval) or time to run from the station.

Default value: No clock synchronization

Set synchronization mode

In the properties dialog box of HW Config, set the synchronization mode as follows:

In AS (on the central I/O bus) : Tab → Diagnostics/Clock (Tab → Diagnostics/Clock)

(Also applicable to MPI on CPU without DP interface)

● For MPI/DP or DP interface: Tab → Clock

● For PROFINET interface: Tab → Clock synchronization

2: interface

The following interfaces support clock synchronization:

● MPI interface

The CPU can be configured as either a time master or a time slave.

● DP interface

The CPU can be configured as either a time master or a time slave.

● PROFINET interface

The clock is synchronized with the CPU on the client through NTP.

● On the automation system in the central rack

The CPU can be configured as either a time master or a time slave.

Instructions

On many of these interfaces, the CPU cannot be used as a time slave.

CPU as time slave station

When acting as a time slave, a CPU receives synchronization frames only from a time master and uses that time as an internal time for that CPU

Between.

The CPU serves as the time master

When acting as a time master, the CPU broadcasts clock-sync frames at set synchronization intervals to synchronize them in the subnet to which they are connected

It stands.

Requirement: The CPU clock is no longer in the default state. The clock must be set at least once.

Clock synchronization as a time master begins with:

● After this time is initialized by SFC 0 "SET_CLK" or programming device function

● Use another time master, provided that the CPU is also programmed as an MPI/DP or PROFINET interface

Time operates from the station.

Instructions

The real-time clock of the CPU is not set in the following cases:

 before delivery

 after the mode selector switch is reset to factory Settings

 After firmware update

3. Point-to-point connection

Stats:

Point-to-point connections allow data to be exchanged over serial interfaces. Point-to-point connections can be used to interconnect programmable controllers, computations

Computer or third party system with communication function. It can also be adjusted according to the procedures of the communication partner.

3.1 Data Consistency

Stats:

A data area is consistent if it can be read or written to in the operating system as a block. Station to station

The data exchanged centrally between them should belong to a whole and originate from a processing cycle, that is, the data is consistent. If user

Programs that include programmed communication capabilities (for example, using XSEND/XRCV to access shared data) can pass

The "BUSY" parameter itself coordinates access to the corresponding data area.

Use the PUT/GET function

For some S7 communication functions that do not require blocks in CPU (server mode) user programs (e.g.,

In terms of PUT/GET or write/read access via OP communication, the scope of data consistency must be considered during programming.

The PUT/GET function of the S7 communication or the read/write variable operation through the OP communication are executed at the cycle control point of the CPU

Fine. To guarantee the defined hardware interrupt response time, the communication variables need to be in the form of blocks of up to 240 bytes, to/from

The copied user memory in the operating system loop control point is continuously copied. There is no guarantee for larger data areas

Data consistency.

Using PUT/GET functions and "Prioritized OCM communication"

If the operation is configured as "OCM communication by priority", the specified data consistency is lost (see the chapter "OP Communication (page 80)"). Therefore, data consistency must be ensured through user programs.

Keep the following consistent:

● Byte, word, double-word access (e.g. LMDx)