Asr With User Program - Hitachi EH-150 Applications Manual

7.3

ASR with user program

Without any user program, EH-ETH2 is able to send / receive data by using cyclic sending and receiving
function. In addition to this function, you can achieve more precise data transmission by using above
function with user program.
EH-ETH2 have sending function shown in Table 7.2.
Sending type
Cyclic sending
Event sending
*1: Program for error detection of communication or other additional operation is required
depending on the occasions.
EH-ETH2 have receiving function shown in Table 7.3.
Receiving type Receive mode
Cyclic receiving
*2: Program for error detection of communication or other additional operation is required
depending on the occasions.
Table 7.2
Communication
control program
EH-ETH2 execute refresh of internal send buffer and data send at
(*1)
Not required
every send cycle automatically
Required User program controls refresh of internal send buffer and data send.
Table 7.3
Communication
control program
Normal Not required
Optional Required
Chapter 7 Automatic Sending/Receiving function (ASR)
Sending function
Description
Receiving function
Receive buffer is refreshed whenever data is received .
(*2)
EH-ETH2 stored EH-ETH2 internal receive buffer data to
receive area in CPU module automatically.
EH-ETH2 stored the receive data, which is permitted to receive
by user program, to a receive buffer of EH-ETH2. After that,
EH-ETH2 refresh receive area in CPU module.
When receive is not permitted, EH-ETH2 nullify received data.
7-17
Description