Yaskawa MP2000iec - Manual (Page 42)

11 MECHATROLINK-II
42 YASKAWA America, Inc. MP2300iec Hardware Manual YAI-SIA-IEC-2R
Operation
Connection to MECHATROLINK
Connect either CN1 or CN2 to the Master-side network, and the other to the extended network.
Arbiter
Two ports CN1 and CN2 are normally in the status ready to receive data. The port that starts receiving data firstbecomes
the data receiving port, and the other becomes the data transmitting port.
Two ports return to the status ready to receive data after having completed receiving or transmitting data. With the
MECHATROLINK-II protocol, the Master station and a slave station transmit data alternately, there will be no conflict of
receiving data between two ports.
LED Indicators for Transmission Status
The LED indicator TX1 or TX2 lights when the port CN1 or CN2 is transmitting data respectively: TX2 lights when CN1
is the data receiving port and CN2 is the data transmitting. TX1 lights when CN1 is the data transmitting port and CN2 is
the data receiving port. However, data are frequently received and transmitted in a short cycle, you can see both indicators
as if they were lit simultaneously. The Master-side LED lights normally darker than the other. It is because the extended
side LED lights when either the Master or a Master-side slave station is transmitting data while the Master-side LED
lights when an extended side slave is transmitting data. Accordingly, the Master-side LED lights more brightly as the
number of extended-side slave stations increases.
• Operation Example of LED Indicators
In this example, CN1 is connected to the Master-side network.
1. TX2 lights when the MECHATROLINK-II Master station is transmitting data.
2. TX2 lights also when receiving response from Slave 1, 2, or 3.
Because the signals sent from Slave 1, 2, and 3 are the CN1 receiving signals for the REP2000.
3. When Slave 4 returns a response, TX1 lights.
As a result, TX2 lights 8 times while TX1 lights once in 1 transmission cycle.