Avtron AV6A Series, Инструкция по эксплуатации

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AV6A 5
CANOpen Protocol “C”
The CANOpen protocol provides a set of data bits inside a CANOpen
message that represent the encoder position (in turns and within 1
turn).
CANOpen may be wired in several different configurations, but the
most common is a “Trunk and Drop Line” configuration. The trunk
message cable must be terminated at each end with 120 ohm
resistors. Note that CANOpen also offers the option to carry device
power to each encoder through an additional cable pair of wires.
Avtron CANOpen encoders with connection caps offer the ability
to act as a “T” coupling in the bus system. This means that the
encoders can effectively be installed in a daisy-chain configuration,
with each encoder wired to the next. The first encoder is typically
wired to the master/scanner device located at one end of the bus,
but the master/scanner device can be located anywhere on the bus
system.
Preferred cable: Twisted pair with individual pair and overall shields.
Communication pair: 24 AWG, copper conductor, capacitance of
50 pF/meter (15 pF/foot) terminated in a 120 Ohm resistive load.
Power pair: 22AWG copper conductor, 17ohms/1000 ft [55 ohms/
km]. Note that resistive losses in long cables may decrease actual
voltage (+Vs) available at the encoder; larger conductors can be
used or the encoder can be powered locally and signal GND brought
through the cable. Maximum transmission speed is limited by cable
length and number of devices as shown in the figures below.
For more details on CANOpen, consult the CiA, CANOpen in
Automation:
www.can-cia.org
Setting Node Number, Baud Rate & Termination Resistor
NOTE: Units with hardware connection caps cannot accept
software-commanded address, baud rate or termination resistor
changes. These must be made using the switches in the connection
cap. Before commencing any changes, check for a connection cap.
It is secured to the rear of the encoder with 2 or 3 screws and due
to snug fit will require a strong pull to remove it after removing the
screws.
NOTE: Any changes to baud rate, node number, or resistor will not
take effect until the encoder is reset (typically power cycled).
Power-Up Sequence
The encoder will power-up in the pre-operational mode.
The message it will issue is:
ID: 0x07nn 0x00
nn=node number, typically:
0x01 for units with connection cap including hardware node and
baud rate selection. (software commands will not change node)
0x20 is the factory default for units with software-selectable
addressing. (software commands can change node number)
Setting Node Number:
To set the node number on units with a connection cap: Set the
address using the two rotating switches. The node number can
be between 0-89. The node address = X10 switch * 10 + X1 + 1
switch value. (The encoder internally adds 1 to the switch value
total). Special addresses are shown below:
Address Function
97 Recovery C2-C5
98 Protocol DS301-V3
99 Protocol DS301-V4
To set the node number on units without a connection cap: write
SDO object 0x3000 using command 0x22. The encoder internally
adds 1 to the written value.
Example, encoder at node 20, change node address to 02:
ID: 0x620 0x22 0x00 0x30 0x00 0x01 0x00 0x00 0x00
Setting Baud Rate:
To set the baud rate on units with a connection cap: Set the baud
rate using the rotating switch marked Bd per the table below.
To set the baud rate on units without a connection cap: write the
baud code per the table below to SDO object 0x3001.
Example, encoder at node 20, change baud rate to 125K = 0x03
ID: 0x620 0x22 0x01 0x30 0x00 0x03 0x00 0x00
Network
Baud
Rate
LSS 1M 500K 250K 125K 50K 20K
Baud
Code or
Switch
Setting
09h 07h 05h 04h 03h 01h 00h
Enabling Termination Resistor:
To enable the termination resistor in units with a connection cap:
Turn switch Rt to “On”.
To enable the termination resistor in units without a connection
cap: write 01 to SDO object 3002h. Ensure any devices on the bus
power up at least 700mS after the encoder with the termination
resistor activated.
Network
Baud
Rate
1M 500K 250K 125K 50K 20K Units
Max.
Length
65
[20]
325
[100]
800
[250]
1600
[500]
3250
[1000]
8200
[2500]
ft
[m]
Max.
Single
Tap
Length
1
[0.3]
15
[5]
15
[5]
15
[5]
200
[60]
500
[150]
ft
[m]
Max.
Total Tap
Length
5
[1.5]
100
[30]
200
[60]
400
[120]
1000
[300]
2500
[750]
ft
[m]
Min. Tap
to Tap
Length
-
[-]
20
[6]
20
[6]
20
[6]
240
[72]
600
[180]
ft
[m]
Number
of
Nodes
2 16 32 64 Units
Max.
Overall
Cable
Length
750
[229]
690
[210]
640
[190]
560
[170]
ft
[m]