Commissioning and configuration
64
MA 255
i
Le
u
ze electronic
Variable configuration of the communication data width
The communication of the MA 2xx
i
with the fieldbus system can be configured with a
variable data width; the upper limit is restricted by the fieldbus. For DeviceNet, a value
between 4 and 240 bytes (120 bytes each for input and output data) can be set.
The small data lengths (< 28 bytes) are particularly of interest for use with bar code scanners
(BCL). The larger data lengths are, on the other hand, relevant for 2D code scanners (hand-
held scanners, LSIS) and RFID.
Notice!
The representation of the (Rockwell) control is usually set to double word (DINT, 4 bytes).
Please observe that in this representation, the byte sequence can vary in contrast to the read
code.
After all parameters have been set in the planning tool/control, the download to the MA 255
i
takes place. The set parameters are now stored on the MA 255
i
.
Afterwards, all MA 255
i
parameters should be stored via upload in the control. This aids in
retaining the parameters during device exchanges, as they a re now also stored centrally in
the control.
Each time a connection is established between the control and the MA 255
i
, these
parameters are now transmitted again to the MA 255
i
. Note that this function must be
supported by the control.
The DeviceNet baud rate is defined for the entire network in the planning tool/control. The
baud rate is set on the MA 255
i
via the S3 baud rate selector switch.
Only if the baud rates are the same is communication with the MA 255
i
possible.
12.4
EDS file - general info
The EDS file contains all identification and communication parameters of the device, as well
as the available objects.
The MA 255
i
is uniquely classified via a class 1 identity object (component of the
MA255i.eds file) for the DeviceNet master.
The identity object contains, among other things, a manufacturer-specific vendor ID, as well
as an ID that describes the principle function of the participant.
The MA 255
i
has the following identity object (class 1):
Vendor ID: 524
dec
./ 20C
H
Device type: 12
dec
/ 0C
H
(labels the MA 255
i
as "communications adapter")
Position sensor type: product type 1004 (specifies the MA 255
i
as "gateway")