Manual

LDU 78.1 Technical Manual, Rev. 12 May 2011
Page 15 of 36
8.2. Calibration Commands – CE, CM n, CI, MR, DS, DP, CZ, CG, ZT, FD,
IZ, ZR, ZI, WT, TM, CS
8.2.1. CE Read TAC* Counter / Open Calibration Sequence
With this command you can read the TAC counter (*TAC = Traceable Access Code) or you can open a
calibration sequence.
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
CE E+00017 (example)
Request: TAC counter CE17
CE 17 OK
Calibration sequence active
This command must be issued PRIOR to any attempt to set the calibration parameters CM n, CI, MR, DS, DP,
CZ, CG, ZT, ZR, FD, LC, LN n or CS. In legal for trade applications the TAC counter can be used to check if
critical parameters have been change without re-verification. After each calibration the TAC counter increases
by 1.
8.2.2. CM n Set Maximum Output Value
This command (CM n with n = 1, 2 or 3) is used to set up the maximum output value (respective the switching
point in multi range applications). Permitted values are from 1 to 99 999.
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
CM 1 M+030000
Request: CM 1 = 30 000 d
CE E+00017 (example)
Request: TAC counter CE17
CE 17 OK
Calibration sequence active
CM 1 50000 OK
Setup: CM 1 = 50 000 d
This value will determine the point at which the output will change to “oooooo”, signifying over-range respective
the point at which the output will change the measuring range / interval size.
Application CM 1 = MAX 1 CM 2 = MAX 2 CM 3 = MAX 3
Single range CM 1 = 1...99 999
CM 2 = 0
(means CM 2 not used)
CM 3 = 0
(means CM 3 not used)
Dual range or dual interval
( Command MR)
CM 1 = 1...MAX 1 CM 2 = MAX 1...99 999
Triple range or triple interval
Teilungen ( Befehl MR)
CM 1 = 1...MAX 1 CM 2 = MAX 1...MAX 2 CM 3 = MAX 2...99 999
It is necessary: 1  MAX 1 < MAX 2 < MAX 3  99 999
Note: The range, in which a scale can be set to zero (SZ) or automatic zero tracking (ZT) is active, is +/- 2% of
CM value. Factory default: CM1 = 99 999, CM 2 = 0, CM 3 = 0
8.2.3. CI Set Minimum Output Value
This command is used to set up the minimum output value. Permitted values are from – 99 999 to 0.
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
CI I–000009
Request: CI = –9 d
CE E+00017 (example)
Request: TAC counter CE17
CE 17 OK
Calibration sequence active
CI –10000 OK
Setup: CI = –10 000 d
This value will determine the point at which the output will change to “uuuuuu”, signifying under-range.
Note: In bipolar applications (e.g. force- or torque measurements) this parameter defines the max. output value
for input signals with negative sign. Factory default: CI = –9
8.2.4. MR Set Multi-range / Multi-interval
This command is only relevant, if CM 2 > 0 or CM 3 > 0. Is this the case,then this command defines, if the
application is multi-range or multi-interval. Permitted values are 0 (Multi-interval) or 1 (Multi-range).
Master (PC / SPS) sends Slave (LDU XX.X) responds Meaning
MR M+00000
Request: MR = 0 (Multi-interval)
CE E+00017 (example)
Request: TAC counter CE17
CE 17 OK
Calibration sequence active
MR 1 OK
Setup: MR = 1 (Multi-range)
Note: Single range applications ignore this parameter.