Manual

LDU 78.1 Technical Manual, Rev. 12 May 2011
Page 14 of 36
8. Commands Description
For better clarity, all commands are divided into groups as described on the following pages.
8.1. System Diagnosis Commands – ID, IV, IS, SR, RS
Use these commands you get the LDU XX.X type, firmware version or device status. These commands are
sent without parameters.
8.1.1. ID Get Device Identity
Master (PC / SPS) sends Slave (LDU XX.X) responds
ID D:7813
The response to this request gives the actual identity of the active device. This is particularly useful when trying
to identify different device types on a bus.
8.1.2. IV Get Firmware Version
Master (PC / SPS) sends Slave (LDU XX.X) responds
IV V:0214
The response to this request gives the firmware version of the active device.
8.1.3. IS Get Device Status
Master (PC / SPS) sends Slave (LDU XX.X) responds
IS
S:067000 (example)
The response to this request comprises of two 3-digit decimal values (067 and 000), which can be decoded
according to the table below:
Leftmost 3-digit value Rightmost 3-digit value
1 Signal stable (no motion) 1 (not used)
2 Zeroing action performed 2 (not used)
3 Tare active 3 (not used)
4 (not used) 4 (not used)
8 (not used) 8 (not used)
16 (not used) 16 (not used)
32 (not used) 32 (not used)
64 (Setpoint-) output 0 active 64 (not used)
128 (Setpoint-) output 1 active 128 (not used)
The example decodes the result S:067000 as follows:
 Signal stable (no motion) [2
0
= 1, LSB]
 Zeroing action performed [2
1
= 2]
 Tare not active [= 0]

Output 0 active [2
7
= 64]
 Output 1 not active [= 0]
Note: The bits that are not used are set to zero.
8.1.4. SR Reset LDU XX.X Firmware
Master (PC / SPS) sends Slave (LDU XX.X) responds
SR OK
This command will respond with ‘OK’ and after maximum 400 ms perform a complete reset of the LDU. It has
the same functionality as power off and on again.
8.1.5. RS Read Serial Number
Issuing the RS command will return the current serial number in the format S:12345678.
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
RS S:123456789
Request: RS = 12345678