Yaskawa DeviceNet Option Card CM05x - Manual (Page 12)

Introducing the DeviceNet Network 1-7
Message Types on DeviceNet
The table below shows the message types that are defined by DeviceNet’s Predefined Master/Slave Connection
Set, as well as which message types are supported by the
Option Board. A definition of each message type follows the table.
Message
Type
DeviceNet
Option Board
Bit-Strobe NO
Change-of-State/Cyclic NO
Polled YES
Explicit YES
The Bit-Strobe Command message is an I/O message that is transmitted by the Master. One Bit-Strobe
Command message can be received by and acted upon by all Slave devices on the network. A Bit-Strobe
Command message provides 1-bit of data to each Slave on the network. Bit-Strobe Command messages are
transmitted by the Master at a set time interval.
The Bit-Strobe Response message is an I/O message that a Slave transmits back to the Master after receiving a
Bit-Strobe Command message. A Bit-Strobe Response message can provide up to 8 bytes of data from a Slave
device to a Master device.
The Option Board does not support Bit-Strobe messaging.
The Change-of-State/Cyclic message is transmitted by either the Master or the Slave. A Change-of-State/Cyclic
message is directed towards a single, specific node. An Acknowledge message may be returned in response to
this message.
The Option Board does not support Change-of-State/Cyclic messaging.
The Polled Command message is an I/O message that is transmitted by the Master. A Polled Command
message is directed towards a single, specific Slave device. A Master must transmit a separate Polled
Command Message for each Slave device that is to be polled. The Polled Command message can provide up to
256-bytes of data to a single Slave device. Polled Command messages are transmitted by the Master at a set
time interval.
The Polled Response message is an I/O message that a Slave transmits back to the Master after receiving a
Polled Command message. A Polled Response message can provide up to 256-bytes of data from a Slave
device to a Master device.
The Option Board uses Polled messaging to receive Run/Stop and Speed commands from the Master and to
send Status and Output information to the Master.
The Explicit Request message is a message that is transmitted by the Master. An Explicit Request message is
directed towards a single, specific Slave device. Explicit Command messages are used to perform services
such as reading data from the Slave device, writing data to the Slave device, and resetting the Slave device.
Explicit Request messages are transmitted by the Master whenever the desired service is required.
The Explicit Response message is a message that a Slave transmits back to the Master after receiving an Explicit
Request message. Explicit Response messages are used to return the results of the Explicit Request message
service.
The Option Board uses Explicit messaging to read Drive data (Drive parameters, Drive runtime status), to write
data (Drive parameters, Drive control commands), to save data (the ENTER command), and to reset the Drive
(power-up reset, out-of-box reset).