migra MPB CAN
Large Format Graphics Compatible LED Display with CANopen Interface
Page 11
microSYST Systemelectronic GmbH, Am Gewerbepark 11, 92670 Windischeschenbach
+49 9681 91960-0,
+49 9681 91960-10, [email protected], www.microsyst.de
3.6
Frame Layout
Frames transmitted to the large format display consist of 3 parts:
Header
Data Unit
Trail
Frames transmitted to the large format display are not evaluated by the
device until 3 to 240 ms after the last frame byte has been received
(receive timeout). The pause between the individual frame bytes may
not exceed this time period!
The next frame can be transmitted immediately after the response frame
has been received.
If no response frame is used, the large format display is not ready to
receive a new frame until the last received frame has been completely
processed. For example, if a large graphic is displayed, a longer waiting
period is required than would be the case for reading out an “online
character”. As a rule, a pause between frames amounting to “receive
timeout plus 150 ms” is sufficient.
The above mentioned receive timeout (3 to 240 ms) also applies if
several different MIGRAs (with different device addresses) are to be
addressed one after the other at the same RS 485 bus.
In order to enable interaction between the PC software (MKS) and an
RS 485 interface, a timeout period of at lest 30 ms must be selected as
a rule.