Leica Biosystems LPC Software installation - Manual (Page 179)

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LabeLase ® Producer - Installation
4.5 Communication protocol
Regardless of whether you are using a Serial COM port or an Ethernet net-
work as your means of connecting to the cassette printer PC, you must still
use a communications protocol to communicate. Although TCP/IP provides
the basic connection level protocol, the application protocol "rides on top of"
TCP.
LabeLase® Producer CL provides several application protocols that you
can use to connect your host system to the cassette printer. Each of these
protocols has its own advantages and disadvantages in areas such as ease
of implementation, reliability, security, etc.
Below, we will discuss each of these protocols and how they may be used.
InfoSight Extended
The Extended protocol is unique to products from InfoSight Corporation and
is available in all of its marking products. The protocol is a master-slave in-
terface, with your host system acting in the role of master. This means that
all transactions are initiated by your system, and the printer will only re-
spond "when spoken to". You will never receive an unexpected message
from the printer. Details of the Extended Protocol are available in this docu-
ment on the InfoSight website.
The Extended Protocol uses a message type field to identify the contents of
each message. Several message types are defined for the LabeLase® Pro-
ducer CL program, but the most important one is the "Download" message.
The Download message is identified by message type "D". The data text field
of the message consists of the Standard Message Format. An example is
shown below.
<SOH> D <STX>stainlesslayout.itl,1,1,A2398,123,Stainless<ETX><BCC><CR>
(note that the block check, BCC, is shown symbolically here.)
The Producer CL program will reply with the following message
<SOH> D <STX><ETX><BCC><CR>
4. Host Communication