Asr With User Program - Hitachi HIDIC EH-150 Applications Manual

7.3

ASR with user program

Without any user program, EH-ETH 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-ETH have sending function shown in table 7.3.1.
Sending type
Cyclic sending
Event sending
*1: Program for error detection of communication or other additional operation is required
depending on the occasions.
EH-ETH have receiving function shown in table 7.3.2.
Receiving type Receive mode
Cyclic receiving
*2: Program for error detection of communication or other additional operation is required
depending on the occasions.
Table 7.3.1 Sending function
Communication
control program
EH-ETH execute refresh of internal send buffer and data send at every
*1
Not required
send cycle automatically
Required User program controls refresh of internal send buffer and data send.
Table 7.3.2 Deceiving function
Communication
control program
Normal Not required
Optional Required
Chapter 7 Automatic Sending/Receiving function (ASR)
Explanation
Receive buffer is refreshed whenever data is received.
*2
EH-ETH stored EH-ETH internal receive buffer data to receive
area in CPU module automatically.
EH-ETH stored the receive data, which is permitted to receive by
user program, to a receive buffer of EH-ETH. After that, EH-
ETH refresh receive area in CPU module.
When receive is not permitted, EH-ETH nullify received data.
7-14
Explanation