Lenze E94AYCDN - Manual (Page 35)

Lenze · E94AYCDN communication module (DeviceNet™) · Communication Manual · DMS 5.0 EN · 02/2014 · TD17
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7 Data transfer
7.2 Telegram types
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7.2 Telegram types
The "I/O data" (process data) and "Explicit Messages (parameter data) telegram types are
transmitted between the host (PLC, scanner) and the drives (devices).
7.2.1 I/O data (process data)
I/O data are transmitted or received according to the producer/consumer principle. There is one
transmitter and no receiver or an optional number of receivers.
• Consumed I/O data: process data from the scanner to the drive (device)
• Produced I/O data: process data from the drive (device) to the scanner
 Assembly Class (0x04 / 4) ( 69)
The following transmission modes are supported:
• Poll I/O data:
The polling command which is transmitted by the scanner includes output data for the device.
The device then transmits its input data to the scanner. The polling response can also be
regarded as an acknowledgement.
• Cyclic I/O data:
The scanner and the device use cyclic I/O data to generate their data independently of each
other, which are then transmitted depending on a timer. The value of the timer must be set by
the user.
• Change of State (CoS) I/O data:
This I/O data type is a special case of cyclic I/O data. CoS nodes always transmit their data if the
state of the data changes.
 Connection Class (0x05 / 5) ( 70)
7.2.2 Explicit messages (parameter data)
Explicit messages serve to configure and parameterise the individual devices of the DeviceNet.
Two nodes have a client/server relationship:
The client transmits a job (request). The server receives this job and tries to accomplish it. The server
then transmits the requested data (positive response) or an error message (negative response).
 Connection Class (0x05 / 5) ( 70)
7.2.3 Device Heartbeat Message
Within a configurable time interval, the device transmits its own device state to the bus via the
Device Heartbeat Message. The Device Heartbeat Message can be configured via the DeviceNet
object Identity Class (0x01 / 1) ( 67) - instance 1, attribute 10.
Adjustable time interval: 1 ... 255 ms