Flintec LDU 69.1 - Manual (Page 24)

LDU 69.1 Technisches Handbuch, Rev. 12 January 2011 Page 24 of 28
8.9. Communication Setup Commands – AD, BR, CL, DX, OP
8.9.1. AD Device Address
This command can set up the device address in the value range from 0 to 255.
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
AD  A:000 Request: Address 0
AD 49
 OK Setup: Address 49
Setting the device address to “0“ will cause the device to be permanently active, listening and responding to
every command on the bus without the need for an OP command. Factory default: AD = 0
Note: After editing the address you first have to save the changes (command WP) and then restart the device.
8.9.2. BR Baud Rate
With this command the following baud rates can be setup: 9 600, 19 200, 38 400, 57 600 and 115 200 Baud.
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
BR  B 9600 Request: 9 600 Baud
BR 115200  OK Setup: 115 200 Baud
Factory default: 9 600 Baud.
In chapter 4.3 an automatic search and adjusting mode for the baud rate is described.
Note: After editing the baud rate you first have to save the changes (command WP) and then restart the
device.
8.9.3. CL Close Device Address n
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
CL 3
 OK Close device #3
CL
 OK Close all connected devices
8.9.4. DX Half-duplex or Full-duplex
With this command the serial communication can be set to half-duplex (DX=0) or full-duplex (DX=1).
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
DX  X:000 Request: DX = 0 (Half-duplex)
DX 1  OK Setup: DX = 1 (Full-duplex)
Factory default: DX = 0 (Half-duplex)
Half duplex communication can be used for 2 wire RS485 communication.
Attention: The auto transmit commands SG, SF and SW will only work if full duplex communication (DX=1) is
selected.
8.9.5. OP Open Device
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
OP  O:00003 Request: Device #3 is open
OP 14  OK Setup: Open device #14
This command, if sent without parameters, requests the address or device number of the device active on the
bus. If sent with parameters, this enables the device defined by the parameters.
The requested device acknowledges its readiness and responds to all bus commands until a further OP
command arrives with a different device address or a CL command is received.
All LDUs operate with an improved communication protocoll:
Each OP command implies a CL command for all non-addressed devices. This simplifies the addressing and
increases the performance within the bus system.