CE3008模块,CE3008培训教程
CPU363端口1和2不按照以下步骤处理奇偶校验错误：使用SNP规范。
SNP规范要求从设备和主设备都回复包含奇偶校验错误的消息，其中2字节NACK消息表示BCC或奇偶校验错误（代码0）。NACK触发来自的重试传输通信合作伙伴。然而，对于CPU363端口1和2，奇偶校验错误是致命的端口未按预期发送NACK消息，SNP主机必须发送新的附加消息以重新建立通信。
CE3008模块在奇偶校验错误和新附加消息之间的时间内，CPU363端口1和2不响应PLC应用程序的COMMREQ。对于例如，尝试使用串行端口设置COMMREQ更改奇偶校验如果奇偶校验的第一个附加消息与硬件配置在COMMREQ之前到达端口。如果主人重新尝试附加消息的频率高于每12秒一次，COMMREQ直到主机停止发送附加消息或SNP电缆已断开。操作说明主题描述用户信息清除时间升级固件用户信息，包括程序、配置、CPU ID（用于SNPRAM内存中的通信）和状态表将自动如果闪存中的CPU固件更改，则清除。你需要如果升级固件，请还原这些。用户程序、配置和参考内存（%R、%AI、%AQ、%I、%Q、%T和%M）表可以从PLC编程器文件夹或闪存恢复。必须设置SNP ID单独使用PLC编程器或HHP。故障、超越和转换表不能存储到闪存中。可以从恢复覆盖程序员或文件夹，但故障和转换丢失。写入闪存当向闪存写入非常大的程序时，可能需要增加编程软件中的请求超时值以避免接收请求超时消息。25秒的上限为通常令人满意
CPU363 ports 1 and 2 do not
handle parity errors in accordance
with the SNP specification.
The SNP specification requires both slave and master devices to reply to
messages that contain parity errors with a 2-byte NACK message indicating a
BCC or Parity Error (code 0). The NACK triggers a re-try transmission from the
communications partner. For CPU363 ports 1 and 2 however, parity errors are
fatal. The ports do not send the NACK message as expected, and the SNP
master must send a new Attach message to re-establish communications.
During the time between the parity error and the new Attach message, CPU363
ports 1 and 2 do not respond to COMMREQs from the PLC application. For
example, attempting to use a serial port setup COMMREQ to change the parity
setting will fail if the first Attach message with parity that is different from the
hardware configuration arrives at the port before the COMMREQ. If the master
re-tries Attach messages more often than every 12 seconds, the COMMREQ
will not be processed until the master stops sending Attach messages or the
SNP cable is disconnected.
Operating Notes
Subject
Description
User Information Cleared when
Upgrading Firmware
User information, consisting of program, configuration, CPU ID (used for SNP
communications), and status tables in RAM memory, will automatically be
cleared if the CPU firmware in flash memory is changed. You will need to
restore these if upgrading firmware. The user program, configuration, and
reference memory (%R, %AI, %AQ, %I, %Q, %T and %M) tables can be
restored from a PLC programmer folder or from flash. The SNP ID must be set
separately, using the PLC programmer or the HHP. The faults, overrides and
transition tables cannot be stored to flash. The overrides may be restored from
the programmer or folder, but the faults and transitions are lost.
Writing to Flash Memory
When writing very large programs to flash memory, it may be necessary to
increase the request timeout value in the programming software to avoid
receiving a request timeout message. An upper bound of 25 seconds is
typically satisfactory
