Chapter 7 Automatic Sending/Receiving function (ASR)
(2) Sending area
Sending area can be specified in EH-ETH2 Configurator of “ASR I/O Area (Connection n
(*1)
) Setting”. One
connection can handle up to 10 sending areas. (One sending area is called as “Entry”)
In case of sending several kinds of I/O areas, they are once sent to a sending buffer according to the setting in
EH-ETH2 Configurator. The following Figure 7.2 shows an example of R0 to R9 (10 bits) and WM100 to WM101
(2 words).
*1 : n means connection No..
EH-ETH2
Send Area Information
Sending buffer
No. I/O Top Size
MSB
LSB
1 R 0 10 H00
R0
R1
R2
R3
R4
R5
R6
R7
2 WM 100 2
H01
R8
R9
0 0
0 0 0 0
…
H02
WM100
High
Byte
…
H03
WM100
Low
Byte
9
H04
WM101
High
Byte
10
H05
WM101
Low
Byte
Figure 7.2
Sending area and sending buffer
Caution
- 1 connection can handle up to 1454 bytes.
- When designated bit size is less than 8 bits (1 byte), the rest bits are all 0.
7.1.2
Automatic data receiving
This function is able to receive data from other EH-ETH2 or host PC to internal buffer and write to
designated receiving area. Users do not have to prepare user program for sending the data from the buffer
to receiving area in CPU.
Ethernet
Host PC
EH-ETH2
Receiving area
Receiving buffer
(B)
(A)
CPU module
(C)
Figure 7.3
Outline of automatic receiving
(A) After the power ON, host PC opens ASR connection between EH-ETH2 and host PC.
(B) After the connection opened, EH-ETH2 waits data from other station.
(C) EH-ETH2 writes received data to receiving area of the CPU.
The specification of automatic data receiving is mentioned as below.
(1) ASR connection
Up to 6 connections are available for the automatic data receiving function. One ASR connection is able to handle
both sending and receiving at the same time.
7-2