Burkert Type 8056 - Manual (Page 100)

- 100 - RS232_485_ETP_MODBUS_BU_REV02.doc
6.
APPENDIX
6.1. RS232 SERIAL PORT
The serial port RS232 present in the aux modules with the RS 232 port option, is used for the connection to printers,
modem, personal computer or other devices. The RS232 port is insulated from all other circuits apart from the RS485
port, with which it shares the power supply.
This type of interface is used to exchange data over short distances (max. 10 metres) with one single user, usually a
PC, a printer or an external modem. The connection takes place through 2 signal lines plus a common line. It has
poor immunity to electrical disturbances and must therefore be made with considerable care in fixed industrial
installation environments.
6.1.1. CONNECTING THE CONVERTER VIA RS232 PORT TO A PRINTER
This connection is made using the aux modules with the RS 232 port option. When the print functions are enabled, the
instrument prints the process data at established intervals or in the event of an alarm. A print command can also be
sent directly from the keyboard. When the RS232 port is used for connecting a printer, the connection cable can be
constructed respecting the following requirements:
• use a shielded cable with at least three wires;
• the shield is connected only to the ML210 end;
• the length must not exceed 10 meters. Remember that the RS232 interface is more susceptible to disturbance
than the RS485 and it is good working practice to minimize the length of the connections;
• on the end for connection to the ML210, fit tips numbered with the terminal number; for the end for connection
to the printer, solder the wires to the pins indicated in the following table on a DB25 MALE type connector; the
printer has a DB25 FEMALE connector (standard for serial RS232 printers);
the connections are the following:
ML210 TERMINAL DIRECTION DB25 PIN
32 (SHIELD) <======> do not connect
25 (TD) =======> 3 (RXD)
23 (CTS) <======= 20 (DTR)
26 (SG) <======> 7 (GND)
ATTENTION: the CTS line must be connected to the DTR line (or equivalent function) of the printer and be used by this
latter to indicate when it can accept data from the converter. The printer must be arranged for HARDWARE
type flow control (not XON/XOFF). If the connections or arrangements indicated are not followed, the display
and the converter keyboard may be blocked indefinitely because they are waiting for printer availability. If the
printer does not use this type of flow control, or if you wish to send the output that would be printed to
another device (PC, digital recorders etc.) you must connect the CTS signal of the converter to a terminal on
the port that supplied a constant voltage of +5 to +15V (DTR or RTS of the PC or of the terminal).
NECESSARY PARAMETERS:
• Menu «7-Communication», function - «Speed 2»: set this value to the same speed as the printer
connected. The speed may be chosen from 2400, 9600, 19200 and 38400 bps
• Menu «7-Communication», function - «Print»: set to «ON» if you wish to use the print functions.
• Menu “7-Comunicazione”, function “Print dos.”: set to “ON” if you wish to use the print functions of
batch.