Specifications

DATAPROCESS EUROPE S.p.A.
ST3xx ST4xx ST5xx
– PROGRAMMING MANUAL -
Pag.13
(approx. 680 labels) unless the buffer is emptied because the external device raises the
CTS. If the cable on the serial is not connected the CTS does not have a clearly defined
CTS level.
The
CTS
line is controlled between each character and the transmission will immediately
stop when the signal becomes negative.
Note: the printer is normally ready to receive until the buffer is full even
when it is printing. However it is possible to configure it (command /$&%) so that
the line is busy (RTS low, XOFF) while each label is being printed thereby keeping it
free (RTS high, XON) only for a short time between labels. There is also a specific
command to keep the printer busy until the reception buffer is empty.
12 Network communication protocols
The communication protocol for the ST3XX, ST4XX and ST5XX printers configured in a
network is basically the same as that described in the previous section except for the fol-
lowing differences:
The printer only works in a network if equipped with an NSA-047/N interface together
with one installed on the PC.
The transmission in network is through a two pole twisted cable (normally a telephone ca-
ble, twisted and shielded for long distances) which connects the computer (with the inter-
face on the serial port) to a maximum of 14 printers and / or applicators. Each interface is
galvanically isolated and can reach a distance of hundreds of metres.
The network’s half-duplex setting has a master-slave communication protocol where the
computer (master) is always the originator of any activity on the line and the printers
(slave) only send data when requested.
The RTS and CTS are no longer used to control the data flow which is now exclusively on
the XON/XOFF mechanism.
Each printer in the network must have a unique address (shown as the "
>Axx
" parameter
printed on the test label), within the range 01 and 14. This is the current maximum num-
ber of printers and / or applicators that can be put into a network. The settings for the net-
work address can be done with either the "
CFG400
” or
WinLW
software packages.
When operating in a network (00<address<15), the printer is inactive by default
when it is switched on (it does not send any data and ignores data received) until it
recognises the appropriate activation sequence which is made up of an ASCII con-
trol character equal to its address plus 16 (code 11 to 1F hex, 17 to 31 dec), followed
by US-US-NAK (code 1F-1F-15 hex, 31-31-21 dec).
When the printer recognises the activation sequence memorised in the reception buffer
and executes the commands which follow the network address, and when the CTS is is
raised, it will send on the line all that it has in the transmission buffer including any re-
sponses to commands received. It will end the string with a terminator character, an EOT