HESG447433R1工控模块卡件
根据指定的模式（例如，如果字12=16，字13，14=9，0，则起始地址将为%I65），该偏移量将以位、字节或字为单位。值的有效范围取决于远程PLC的内存范围。（字15）远程PLC-存储单元数：字15指定要传输的数据量。输入的值是要传输的存储器单元数，其中远程PLC存储器类型（位、字节或字）的大小在字12中指定。（字16）远程PLC-网络地址类型：字16指定远程PLC地址的格式。单词16必须包含值1。这表示使用每个十进制数字的单独寄存器表示的虚线十进制IP地址。（字17）远程PLC-网络地址长度：字17指定此COMMREQ命令块中远程PLC IP地址的字长度。单词17必须包含4。（字18-21）远程PLC-IP地址：字18-21指定要访问的远程PLC的虚线十进制IP地址的四个整数，每个字一个整数。PAC系统™ RX3i和RSTi EP TCP/IP以太网通信用户手册第6节GFK-2224Y 2019年8月编程EGD命令119 6.7读取EGD交换机（4002）读取EGD交换命令可用于从生产者或消费者交换机读取全部或部分数据。此命令使用其配置的生产者ID和Exchange ID标识要读取的数据。然后，它可以直接从生产者或消费者设备内存中读取交换的数据内容。该命令可发送至PACSystems PLC和其他EGD 2类设备。在PACSystems PLC中，读取EGD交换读取配置为在交换中以指定偏移传输的PLC参考存储器位置。因此，将读取当前流程数据，而不是上次在交换中传输的数据。6.7.1读取EGD交换命令块字偏移值描述字1命令数据块的长度始终为19字2 0始终为0（无等待模式请求）字3（参见第112页的表格）COMMREQ状态字4的存储器类型基于COMMREQ的状态字5 0保留字6 0保留字7 4002（fa2H）读取EGD Exchange命令编号。Word 8重试时间，以毫秒为单位命令传输重试之间的时间。默认值为1000ms。字9本地读缓冲存储器类型本地PLC中数据的存储器类型。字10本地读缓冲区参考表起始地址（最低有效字）基于1的偏移（续…）存储器位置1-11的进一步考虑（字7）EGD命令号：字7请求发生读EGD交换操作。如果命令处理成功，将导致从客户端向服务器读取来自指定EGD交换的数据。（Word 8）命令重试时间：Word 8指定传输命令时以太网接口在重试之间等待的时间（以毫秒为单位）。总共将尝试四次发送命令。如果在四次尝试之后（即四次重试时间值之后）没有收到响应，则COMMREQ状态字中将返回错误状态。如果命令重试指定为零，则使用默认值1秒。（字9）本地PLC–存储器类型：字9-11指定本地PLC中以太网接口将从远程EGD设备读取数据的位置。Word 9的有效值列在“读取PLC内存命令”的说明中。要传输的数据量由Exchange DataLength（字18）指定。
This offset will be either in bits, bytes, or words depending on the mode specified (for example, if Word 12=16 and Words 13,14 =9, 0, then the starting address will be %I65). Valid ranges of values depend on the remote PLC’s memory ranges. (Word 15) Remote PLC - Number of Memory Units: Word 15 specifies the amount of data to be transferred. The value entered is the number of memory units to be transferred, where the size of the remote PLC memory type (bit, byte, or word) is specified in Word 12. (Word 16) Remote PLC - Network Address Type: Word 16 specifies the format of the remote PLC address. Word 16 must contain the value 1. This indicates a dotted-decimal IP address expressed using a separate register for each decimal digit. (Word 17) Remote PLC - Network Address Length: Word 17 specifies the length in words of the remote PLC IP address in this COMMREQ Command Block. Word 17 must contain 4. (Words 18 – 21) Remote PLC - IP Address: Words 18–21 specify the four integers, one integer per word, of the dotted-decimal IP address of the remote PLC to be accessed. PACSystems™ RX3i and RSTi-EP TCP/IP Ethernet Communications User Manual Section 6 GFK-2224Y August 2019 Programming EGD Commands 119 6.7 Read EGD Exchange (4002) The Read EGD Exchange command can be used to read full or partial data from a producer or the consumer exchange. This command identifies the data to be read using its configured Producer ID and Exchange ID. It can then read the content of the data for the exchange, directly from the producer or consumer device memory. This command can be sent to PACSystems PLCs and to other EGD Class 2 devices. In a PACSystems PLC, reading an EGD exchange reads the PLC reference memory locations configured to be transferred at the specified offset in the exchange. Thus, current process data will be read, not the data that was transferred last in the exchange. 6.7.1 Read EGD Exchange Command Block Word Offset Value Description Word 1 Length of command data block Always 19 Word 2 0 Always 0 (no-wait mode request) Word 3 (See table on page 112) Memory type of COMMREQ Status Word Word 4 0-based Offset of COMMREQ Status Word Word 5 0 Reserved Word 6 0 Reserved Word 7 4002 (fa2H) Read EGD Exchange command number. Word 8 Retry time, in milliseconds The time between retries of command transfers. Default is 1000ms. Word 9 Local read buffer memory type Memory type for the data, in the local PLC. Word 10 Local read buffer reference table starting address (least significant word) 1-based offset (Continued …) Further Consideration of Memory Locations 1-11 (Word 7) EGD Command Number: Word 7 requests that a read EGD exchange operation occur. If the command is processed successfully, it will result in data from a specified EGD exchange being read from the client to the server. (Word 8) Command Retry Time: Word 8 specifies the time (in milliseconds) the Ethernet interface will wait between retries when transferring the command. A total of four tries will be made to send the command. If no response is received after the four tries (i.e. after four times the retry time value), an error status will be returned in the COMMREQ status word. If the command retry is specified as zero, the default value of one second is used. (Word 9) Local PLC – Memory Type: Words 9-11 specify the location in the local PLC where the Ethernet interface will get the data to be read from the remote EGD device. Valid values for Word 9 are listed in the description of Read PLC Memory Command. The amount of data to be transferred is specified by the Exchange DataLength (Word 18).
