Mode; Prot; Wiring Instructions; Rs 422 Command Sequences - SICK DME3000-2 RS 422 Gebrauchsanweisung

DME 3000-2 _ _
Software 1.1

4.2.7.3 MODE

Select the type of data transfer:
CONTINUOUS:
REQUEST:

4.2.7.4 PROT

Data output protocol
+ / - PROT: S D D D D D D
S = sign ( + / - ASCII), D = decimal character (0...9 ASCII).
The data is output cyclically in accordance with the defined baud rate setting.
CRLF PROT: S D D D D D D
The data is output cyclically in accordance with the defined baud rate setting.
BCP: Not used
CP: Not used

4.2.7.5 Wiring instructions

The RS 422 standard fulfills the requirements for rapid, reliable data transfer. This interface is
implemented for serial data transfer in full duplex mode with a transfer rate of up to 10 Mbaud and a
line length of 1000 m (DIN 66259, part 3). The interface is operated with a transmit data channel (T)
and a receive data channel (R). The high transfer reliability is achieved by evaluating the differential
voltage between a twisted wire pair in each case.
Note
Shielded twisted wire pairs are recommended for a reliable data transfer. A comprehen-
sive shield concept that functions faultlessly is required for interference-free data trans-
i
fer. Special attention must be paid to grounding of the cable shield to the switching cabi-
net and the DME 3000. The cable shield of the ready made cable is connected with the
metal plug and consequently with the DME housing. The complete cable shield on the
switching cabinet must be connected with the system ground. Potential compensating
current via the cable shield is prevented by a suitable ground cable.

4.2.7.6 RS 422 command sequences

The RS 422 command sequences enable status messages to be read out and the DME 3000
parameters to be defined via the serial interface.
A command sequence is structured as follows:
STX Start Of Text (02H = CTRL B)
CCC 3 ASCII characters (A...Z, 0...9). Each command sequence is defined by an identifier (see
following table)
DD 1 data string ( maximum 7 ASCII characters)
EOT End Of Transmission (04H = CTRL D)
Cyclical data transfer in accordance with the defined baud rate setting
Data transfer on request only. Format: STX TSM EOT (see Chap. 4.2.7.6)
CR LF
STX CCC <DD> EOT
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