KR19980083753A - Master-Slave Multiplexing Protocol - Google Patents

Abstract

The present invention relates to a data communication control method, and more particularly, to a master-slave multiplexing protocol method that independently controls a plurality of slaves by one command transmission from a master and independently accesses request information from them. The multiplexing protocol method is efficiently used in a data communication device between a master device and a master-slave having a plurality of slave devices connected to the master device. A master data frame transmission step of multiplexing a plurality of command data corresponding to a step of receiving and the state and processing request information of each of the slaves and transmitting the same to a data frame having a common address, and a common address is set to the slaves, A slave receiving step of receiving a data frame having the common address, receiving magnetic data corresponding to a preset position, and executing a command; and performing a command by receiving the magnetic data, and then replacing its common address with a unique address change Set with the information on the locations of their condition and request, the slave address comprises the step of changing changes to the common address.

Description

Master-Slave Multiplexing Protocol

The present invention relates to a method for controlling transmission and reception of a protocol between master and slaves, and more particularly, to a multiplexing protocol between master and slaves capable of independently controlling a plurality of slaves by a single command transmission and independently accessing request information from them. It is about.

Typically, in a digital communication device, a relationship in which one master controls several slaves independently (individually) is referred to as a master-slave control scheme. In such a master-slave control system, a protocol for transmitting and receiving protocol data between a master device and a plurality of slaves is provided, and such a configuration can implement a serial communication method.

1 is a block diagram for a master-slave protocol according to the prior art. In the drawings, reference numerals S1, S2, S3, and S4 are assigned independent independent addresses, and are a plurality of slave devices that receive a specific function in response to receiving an execution command including the unique address. At this time, the plurality of slave devices Si (where i is an integer of 1. 2, 3, 4) has a function of storing the execution state of the execution command and information of the requirements together with a unique address in an internal register. The MA is a master device that accesses information on the status and requirements of the plurality of slaves Si and transmits an execution command with a unique address of the plurality of slave devices Si.

FIG. 2 is a diagram illustrating a configuration of a protocol transmission / reception data format between a master and a slave according to the related art, and it can be seen that data transmitted and received between a master device and a slave device is serial communication.

In FIG. 2, the STA is a start bit, the Si address is an address designating the i-th slave, P is bits for ensuring indetermination of data such as parity bits or a cycle redundancy check (CRC), and Si data is Control command data for controlling the i slave, and STO is a stop bit.

First, an operation process in which one master device MA reads and individually controls information of a plurality of slave devices Si will be briefly described with reference to FIGS. 1 and 2.

Now, when the master-slave device as shown in FIG. 1 is operated, the master device MA reads information of the slave devices S1, S2, S3, and S4 in a polling manner in order to determine the state of the plurality of slave devices Si. At this time, the information of the slave devices S1, S2, S3, and S4 stores the unique address of the slave itself, information indicating the operation state of the slave itself, and information of requirements (information required by the master).

The master device MA grasping the requirements of each of the plurality of slaves Si by the above process sends a control command for executing specific slaves having the request information. At this time, the format of the data frame of the control command sent from the master MA to the specific slave is as shown in FIG. That is, the address of the slave for designating the specific slave and the data frame for controlling the operation of the slave are sequentially transmitted.

A plurality of slaves Si each receiving a data frame transmitted in the form as shown in FIG. 2 from the master device MA compares an address included in the received data frame with its own address and receives subsequent data only when the same is identical. Perform the function for the corresponding control command. Therefore, when the address of the data frame sent from the master device MA is S1, only the slave S1 among the plurality of slaves Si receives this and executes the corresponding function.

However, the conventional protocol transmission / reception method using the data format as shown in FIG. 2 is a method of transmitting a slave-specific address together when the master device MA transmits data to a specific slave device, thereby transmitting control commands to a plurality of slaves. In this case, there is a communication overhead in that all addresses of the slaves must be sent before data, resulting in communication failure.

Accordingly, an object of the present invention is to provide a method for multiplexing and transmitting a protocol of a master-slave composed of one master device and a plurality of slave devices at high speed.

Another object of the present invention is to propose a protocol that provides a method for efficiently executing data transmission and reception with a master by a plurality of slave devices selectively changing their reception addresses.

The present invention for achieving the above object, in the protocol multiplexing between a master and a slave having a master device and a plurality of slave devices connected to the master, the state of the master through a unique address set to each of the plurality of slaves And a master data block transmission step of receiving processing request information through a polling method, multiplexing a plurality of command data frames corresponding to the configuration information of each of the slaves, and transmitting the multiple command data frames to a data block having a common address; A slave execution step of receiving a data block having a data block and receiving a magnetic data corresponding to a preset position, and performing a command by receiving the magnetic data; Polling Give the authority to the dew label features a slave made of an common address changing step of shifting the locations of their condition and request sent to the master haejugo a common address.

1 is a block diagram for a master-slave protocol according to the prior art.

2 is a block diagram of a protocol transmission and reception data format between a master and a slave according to the prior art.

3 is a diagram for describing a process of transmitting and receiving a protocol between a master and a slave according to an embodiment of the present invention.

4 is a diagram illustrating a configuration of a data frame in which a master requests execution from a slave according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings of the embodiments of the present invention, those having substantially the same configuration and function as those in the above-described drawings will use the same reference numerals. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to obscure the subject matter of the present invention.

3 is a diagram for describing a process of transmitting and receiving a protocol between a master and a slave according to an embodiment of the present invention. In FIG. 3, reference numeral 10 denotes a path through which the master device MA multiplexes and transmits command data to be transmitted to a plurality of slave devices S1, S2, S3, and S4 in a data frame of a common address. 18 represents a path in which a plurality of slave devices S1, S2, S3, and S4 each transmit information of their status and requirements to the master device MA when the master is authorized by the polling method, and at this time, a data frame Has the address + data structure found in normal serial communication. Here, all the paths 10, 12, 14, 16, and 18 are logical paths formed through a common bus connected between the master device MA and the plurality of slaves S1, S2, S3, and S4, and path 11 is actually a master path. A physical data bus connected between slaves.

4 is a configuration of a data frame and a data block of a master device according to an embodiment of the present invention, in which command S1 data, S2 data, S3 data, and S4 data to be transmitted to a plurality of slave devices S1, S2, S3, and S4 are common addresses; Shows multiplexing to a data frame. Here, P is a parity bit or bits that guarantee the integrity of data such as CRC, and may be absent.

First, prior to describing the preferred embodiment according to the present invention with reference to FIGS. 3 and 4, all slave devices Si change to their own addresses after performing a command sent from the master device MA, Assume that you are ready to send status and requirements information to the master.

Now, when the master-slave device shown in FIG. 3 is operated, the master device MA uses the paths 12, 14, 16, and 18 to request the status and request of the slaves set in the registers of the plurality of slave devices S1, S2, S3, and S4. Read the information separately. For example, the master device MA initially receives a status of the slave device S1 and information of requirements by designating a unique address set in the slave device S1. At this time, the S1 send request frame sent by the master to receive the status information child request of the slave S1 is the address set in the slave device S1 so that the other slave devices S2, S3, and S4 do not respond to the frame. It is waiting for the frame of the master including its address.

After the slave S1 transmits the data set in the slave device S1 to the master as described above, the slave device S1 replaces the address with a common address and prepares to execute the frame sent by the master in the next state. When the master device MA receives all the configuration information of the plurality of slave device Sis in this manner, the addresses of all the slave device Sis are set to a common address, and the state transitions to a waiting state for an execution command from the master device MA.

After reading the requirements of all slave device Sis, the master device MA generates command data for operating the plurality of slaves according to the requirements of the slave devices Si, and the generated command data of the plurality of slaves is shown in FIG. As shown in FIG. 4, path 10 is multiplexed into one data frame having several execution data frames. In this case, referring to the multiplexed data block as shown in FIG. 4, a common address in which all slaves Si are receivable is transmitted first, and then data frames of the slaves are sequentially transmitted.

At this time, since the addresses of the plurality of slaves Si are all changed to the same common address, the slaves simultaneously receive the multiplexed data blocks having the common address as shown in FIG. That is, the plurality of slaves Si receive only their position data by counting using the distinguishing bits of the STA and the STO of the data frame that are continuously input in response to the reception of the common address. For example, in the case of the second slave device S2, after the common address is input, the data frame is counted by the STA and the STO, and only the S2 data frame input as the second frame is received to perform a corresponding command.

When the master device MA transmits a multiplexed data block by the above operation, a plurality of slaves Si having a common address receive all of them and operate by receiving data of a magnetic frame among the multiplexed data frames. Can be increased. For example, if the address of the slave device is configured with 8 bits, data transmission loss of (n-1) * 8 can be prevented when transmitting data to n slaves.

As described above, in the present invention, when the master-slave protocol is transmitted and received, the master can transmit commands of a plurality of slaves at one time, thereby reducing the amount of data on the network and thus operating at a higher speed.

Claims (1)

In a multiplexing protocol between a master and a slave having one master device and a plurality of slave devices connected thereto, The master sequentially grants transmission authority to each slave having a unique address so as to receive the slave's own execution status and request from each slave in sequence, and each slave having transmitted the information is executed in the next step. A slave common address changing step of changing the address of the residual to the slave common address for receiving a command; Data frames for controlling each slave and one common address changed by each slave in a previous step when the master converts the information received from each slave into control data and transmits the plurality of control data to the slaves. A master data block transfer step of constructing and transmitting a data block with A slave execution step in which the slaves simultaneously receive a data block having the common address and select a magnetic data frame corresponding to a preset position to execute a command; After the slave performs the execution name by receiving the magnetic data frame, the slave master address change step of changing the slave common address back to its own unique address and returning to the first step. Multiplexing protocol between slaves.