4-42
4. TNU functions
TNU
5.
TACnet communication specifications
5-1
TACnet communication overview
Communication speed
38.4 kbps, 57.6 kbps, 115.2 kbps (Standard: 115.2 kbps)
Communication cycle
20 msec (per axis)
Communication method
Half-duplex Broadcast method
Retry
None
Transmission channel type
RS-485
Error control method
No parity, CRC-CCITT (X
16
+X
12
+X
5
+1)
5-2
TACnet communication status transition diagram
• The TNU status transits by the mode change switch
(-> P.5-3)
.
SW = 0 indicates the IO mode (up), SW = 1 indicates PC/TDO mode (down).
In the IO mode, there is regular transmission/reception of the I/O information
from each slave, and an interrupting communication is conducted
(-> P.4-44)
.
at the regular transmission/reception of the interval of interrupting communications.
* Interrupting communication decreases the time required for regular transmission/reception.
TNU Firmware previous to Ver 1.2
PC
mode
SW= 1
SW= 0
SW= 1
SW= 0
Initialization
TNU
Power ON status
IO mode
IO mode
communication
The I/O
command
information from
the master device
is updated
Transmission/
reception
from/to TJU
Transmit to
PC/TDO
Transmission/
reception
from/to TJU
Reception from
PC/TDO
Interrupting
communication
Reception
from PC/TDO
Transmission/
reception
from/to TJU
Transmit to
PC/TDO
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