LDU 179.1 Technical Manual rev. 1.10 - February 2019 Page 31 of 45
8.4.3. UR Update Rate and Averaging
[ SDO 2100 sub 11 ]
Depending on the selected filter mode this command defines an averaging for the output value. The permitted
settings are from 0 to 7 (see table below
). The average value is always calculated from
2
UR
measurement
values.
LDU 179.1 allows for the following settings:
UR
0
1
2
3
4
5
6
7
Average of 2
UR
values
1
2
4
8
16
32
64
128
Check / Setup of the averaging:
Master (PC / SPS) sends
Slave (LDU 179.1) responds
Meaning
UR
U+00003
Request: Averaging of 8 values
UR7
OK
Setup: Averaging of 128 values
WP
OK
Setup saved
Default setting:
0
8.5.
Taring and Zeroing Commands
– SZ, ZA, RZ, ST, RT, SP
The following commands allow you to set and reset the zero and tare values. The zero set up during calibration
remains the ‘true zero’ but the new ‘current zero’ can be set up by using the SZ command. If the SZ command
is issued and accepted then all weight values will then be based on the new ‘current zero’. Please remember
that the zero value will be subject to the Zero tracking function if enabled. If the weight signal is not stable (as
defined by the No motion range NR and the No motion time NT) then both the set zero SZ and set tare ST
commands will be disabled. Also the Set Zero SZ command is not allowed if the new zero value required and
the ‘calibration zero’ differ by more than 2 % of the CM value (maximum allowable value).
See chapter 9 Used in “Approved” applications.
8.5.1. SZ Set System Zero
[ RPDO1,02 ]
This command sets a new “current zero” which is then the basis of all weight values until further updated by the
zero tracking functio
n, another SZ command or the “reset zero” command RZ.
Master (PC / SPS) sends
Slave (LDU 179.1.1) responds
Meaning
SZ
OK
Set zero performed
The SZ command will fail (LDU 179.1
responds with ERR) if the new “current zero” is more than 2% (of the CM
value) higher or lower than the “true zero” set during calibration. The SZ command will also fail if the weight
signal is not stable as defined by the No motion range (NR) and the No motion time (NT). If the weight signal is
“stable”, the response to the IS command (Device Status) will show the “signal stable” bit active and the SZ
command will be accepted (OK). If the “signal stable” bit is not active, the SZ command will be rejected and the
LDU will respond with ERR (error).
8.5.2. ZA Set Averaged System Zero
[ n.a. ]
This command will set the system zero as SZ, but using an average over the
TI
time period.
8.5.3. RZ Reset Zero
[ RPDO1,01 ]
This command cancels the SZ command and the zero reading reverts to that set by the CZ command during
calibration.
Master (PC / SPS) sends
Slave (LDU 179.1) responds
Meaning
RZ
OK
Zero point CZ active
The LDU
responds to the RZ command with either OK or ERR. If OK is returned then the “zero action
performed” bit in the Device Status (IS) response will be set to “0”.
