CE3008模塊,CE3008培訓(xùn)教程
CPU363端口1和2不按照以下步驟處理奇偶校驗錯誤：使用SNP規(guī)范。
SNP規(guī)范要求從設(shè)備和主設(shè)備都回復(fù)包含奇偶校驗錯誤的消息，其中2字節(jié)NACK消息表示BCC或奇偶校驗錯誤（代碼0）。NACK觸發(fā)來自的重試傳輸通信合作伙伴。然而，對于CPU363端口1和2，奇偶校驗錯誤是致命的端口未按預(yù)期發(fā)送NACK消息，SNP主機(jī)必須發(fā)送新的附加消息以重新建立通信。
CE3008模塊在奇偶校驗錯誤和新附加消息之間的時間內(nèi)，CPU363端口1和2不響應(yīng)PLC應(yīng)用程序的COMMREQ。對于例如，嘗試使用串行端口設(shè)置COMMREQ更改奇偶校驗如果奇偶校驗的第一個附加消息與硬件配置在COMMREQ之前到達(dá)端口。如果主人重新嘗試附加消息的頻率高于每12秒一次，COMMREQ直到主機(jī)停止發(fā)送附加消息或SNP電纜已斷開。操作說明主題描述用戶信息清除時間升級固件用戶信息，包括程序、配置、CPU ID（用于SNPRAM內(nèi)存中的通信）和狀態(tài)表將自動如果閃存中的CPU固件更改，則清除。你需要如果升級固件，請還原這些。用戶程序、配置和參考內(nèi)存（%R、%AI、%AQ、%I、%Q、%T和%M）表可以從PLC編程器文件夾或閃存恢復(fù)。必須設(shè)置SNP ID單獨使用PLC編程器或HHP。故障、超越和轉(zhuǎn)換表不能存儲到閃存中?？梢詮幕謴?fù)覆蓋程序員或文件夾，但故障和轉(zhuǎn)換丟失。寫入閃存當(dāng)向閃存寫入非常大的程序時，可能需要增加編程軟件中的請求超時值以避免接收請求超時消息。25秒的上限為通常令人滿意
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
