ASTECH VLM500-DG User manual

User manual
VLM500-DG
Version 1.6

VLM500-DG User manual Contents
page 2 ASTECH GmbH
Remarks
The nformat on prov ded n the manual on hand have been carefully nvest gated and processed. St ll, we cannot
assume any k nd of l ab l ty regard ng completeness or m stakes. However, we are always grateful to get feedback
and proposals.
Cla ms for damages are, except n the case of premed tat on or negl gence, n pr nc ple excluded.
As a ser es of vers ons of th s product s ava lable, dev at ons from the manual on hand m ght occur, f appl cable.
We reserve ourselves the r ght to mplement techn cal mod f cat on that serves to opt m ze of the product
w thout related not f cat on. Thus, t cannot be assumed that subsequent product vers ons show the same
propert es as the one on hand.
Reg stered trademarks are the manufacturer’s property.
VLM500-DG – User manual V1.6
Copyr ght © ASTECH Angewandte Sensortechn k GmbH, Rostock 2018-2021
VLM500-Ser e from Hardware vers on 2019, F rmware Vers on from V1.52R3
Date of pr nt ng: 17.05.2021
Revision history
Revision Date Changes
1.6 12.12.2023 Descr pt on of command “SYNCODO” changed
Prof net-parameter zat on added
1.5 10.03.2021 Error codes changed
Command “SYNCODO” added
Chapter “Test mode” added
1.4 16.09.2020 F rst Engl sh release
ASTECH GmbH, Schonenfahrerstr. 5, D-18057 Rostock
Internet: www.astech.de E-Ma l: [e-mail]
Telephone: +49 (0)381 / 44073-0 Telefax: +49 (0)381 / 44073-20

Contents VLM500-DG User manual
ASTECH GmbH
page
3
. Table of contents
1 General nformat on ................................................................................................................................. 5
1.1 Introduct on ........................................................................................................................................ 5
1.2 Mode of operat on .............................................................................................................................. 6
2 Data transm ss on ................................................................................................................................... 10
2.1 Prof net ............................................................................................................................................. 10
2.2 Ethernet ............................................................................................................................................ 15
3 Programm ng .......................................................................................................................................... 19
4 Test mode .............................................................................................................................................. 24
5 Error messages ....................................................................................................................................... 25
6 Dev ce cabl ng......................................................................................................................................... 26
7 W r ng plan ............................................................................................................................................. 27
. Commands and parameters of the VLM500-DG
Sync ............................................................................................................................................................... 21
Syncauto ......................................................................................................................................................... 21
Syncbasis ........................................................................................................................................................ 21
Synccalc .......................................................................................................................................................... 22
Synclength ...................................................................................................................................................... 22
Syncodo .......................................................................................................................................................... 22
Syncoutput ..................................................................................................................................................... 22
Syncrefresh ..................................................................................................................................................... 23
Syncstart......................................................................................................................................................... 23
Syncstate ........................................................................................................................................................ 23
Syncstop ......................................................................................................................................................... 23
. List of figures
F gure 1: Pr nc ple of a sk n pass m ll w th the VLM500-DG system..................................................................... 5
F gure 2: Example of a r ng buffer of s ze 12 ...................................................................................................... 6
F gure 3: Pos t on of dev ces .............................................................................................................................. 7
F gure 4: Measurement accuracy under laboratory cond t ons........................................................................... 9
F gure 5: Status page of the ntegrated webserver ........................................................................................... 10
F gure 6: Telnet menu to conf gure the UDP and TCP channel.......................................................................... 16

VLM500-DG User manual Contents
page 4 ASTECH GmbH
F gure 7: VLMTool w th new tab "DG-Opt on" ................................................................................................. 19
F gure 8: Tunnel mode off ............................................................................................................................... 20
F gure 9: Tunnel mode on ............................................................................................................................... 20
F gure 10: Reference po nts for process calculat on ......................................................................................... 21
F gure 11: Sync Analyzer ................................................................................................................................. 24
F gure 12: cabl ng of VLM500-DG system ........................................................................................................ 26
F gure 13: W r ng plan ..................................................................................................................................... 27
V. List of tables
Table 1: VLM500 Prof net modes (Prof net IN)................................................................................................. 11
Table 2: M n mum output t mes (all values n ms)............................................................................................ 12
Table 3: Adjustable VLM500-DG-Parameter v a Prof net .................................................................................. 12
Table 4: Dev ce status ..................................................................................................................................... 14
Table 5: Control byte for Prof net OUT ............................................................................................................ 14
Table 6: VLM500-DG Data stream v a UDP....................................................................................................... 17
Table 7: Prof net dev ce status ........................................................................................................................ 17
Table 8: Controlbyte IFFE ................................................................................................................................ 18
Table 9: Format control byte TCP .................................................................................................................... 18
Table 10: Sett ng range of the parameter SYNCBASIS....................................................................................... 22
Table 11: Sett ngs for SO2 ............................................................................................................................... 23
Table 12: Error l st ........................................................................................................................................... 25

General nformat on VLM500-DG User manual
ASTECH GmbH page 5
1 General information
1.1 ntroduction
Th s manual descr bes the software and hardware of the VLM500 – DG sk n pass measur ng system. It s a
supplementary manual for the VLM500 speed and length measur ng gauge.
The DG system cons sts of up to three VLM500 dev ces that are w red to one another and that automat cally
calculate and output d fferent al values. Th s system was spec ally developed for use n sk n-pass, stretch ng and
roll ng stands n the steel and alum num ndustr es.
The system cons sts of a master VLM500 (DG master) and at least one slave (DG slave 1), as shown n F gure 1.
Opt onally, a second slave (DG slave 2) can be connected n order, to add t onally determ ne the degree of
stretch ng. The calculat ons of the d fferent al values (sk n-pass and stretch ng degree) are carr ed out n the DG-
Master. The calculat ons are based on lengths, not on veloc t es. Th s leads to more accurate values, because
fluctuat ons n speed are cons dered. A separate evaluat on un t s not requ red. Dur ng the commun cat on
between the DG-Master and the DG-Slave and the calculat on of the mass flow values, the busy LED n the cover
of the DG-Master l ghts up yellow.
Figure 1: Principle of a skin pass mill with the VLM500-DG system
It s recommended to place the DG-master n the nfeed of the system. DG-slave 1 comes to the outfeed. In case
that a second slave dev ce s nstalled, t s placed n the further / subsequent outfeed. The parameter "SYNCBASIS"
can be used to set wh ch dev ce the calculated values refer to, .e. whether they refer to the nfeed or the outfeed.
For the calculat on of the mass flow values, t s rrelevant whether the respect ve VLM500 s mounted n the
d rect on of object movement1 or aga nst the d rect on of object movement. In the case the VLM500 s mounted
reversely (aga nst the d rect on of object movement), the "DIRECTION" parameter of the correspond ng VLM must
be adapted. If, for example, the DG master s nstalled reversely, the "DIRECTION" parameter must be set to the
value 1 n the master. Otherw se 0. Both VLM500 are programmed to "DIRECTION 0" by default. If poss ble, t s
recommended to nstall the dev ces n the d rect on of movement.
1 d rect on of object movement means that the measurement object moves from the hous ng base to the
hous ng cover of the VLM.

VLM500-DG User manual General nformat on
page 6 ASTECH GmbH
1.2 Mode of operation
Start of calculation
After all dev ces are connected and sw tched on, the "SYNCSTART" command must be executed n the DG-Master.
Th s can be ach eved n two ways: n the case of a Prof net connect on, b t 2 ("SYNCSTART") must be set n the
control byte (see sect on 2). Or the command can send to the DG slave v a the programm ng nterface. If the sk n
pass measurement and the opt onal degree of stretch ng measurement are to take place automat cally after the
dev ces are sw tched on, the parameter SYNCAUTO must be set to “1” and permanently saved n the DG-Master.
When SYNCSTART s executed, all dev ces connected to the master rece ve a start tr gger pulse. As soon as the
object to be measured (e.g. steel str p) starts mov ng, all dev ces record the length of the mater al passed n the r
f eld of v s on (l ke a normal VLM500). If the measured length n the DG-Master s greater than or equal to the
conf gured refresh length (command SYNCREFRESH), another tr gger pulse s output synchronously to all
connected dev ces. These save the length recorded up to that po nt and mmed ately start a new length
measurement. In the meant me, the DG-Master quer es the saved lengths from the slave dev ces one after the
other. The length segments are added to the prev ous length values and stored n a r ng memory. The ntegrat on
takes place unt l the parameter zed measurement length (command SYNCLENGTH) s reached. The r ng buffer s
treated accord ng the FIFO (F rst In F rst Out) pr nc ple.
F gure 2 shows an example of a c rcular buffer w th 12 f elds. W th each update step, a new length element that s
one refresh length longer, s nserted nto the r ng buffer. When the buffer s full and the oldest value s removed.
The s ze n of the r ng memory results from the quot ent of the measurement length to the refresh length.
Figure 2: Example of a ring buffer of size 12
By default, the calculat on of values s not act ve after power ng up the system. By sett ng the
parameter SYNCAUTO to 1 ( n the master dev ce), the calculat on starts after power-up.
Th s setup requ res a sequent al start-up where the slaves have to be powered before the DG-
master. Otherw se there w ll be commun cat on errors

General nformat on VLM500-DG User manual
ASTECH GmbH page 7
Filter behavior of the ring buffer
The pr nc ple of the r ng buffer corresponds to that of a low-pass f lter. Th s means that changes to the sk n pass
character st cs are delayed by the VLM500-DG depend ng on the dynam cs. To est mate the delay t me, wh ch s
actually a length, the follow ng s mpl f ed approach appl es:
The t me constant τ s used from the analys s of l near dynam c systems. τ s the t me after wh ch the response of
a system has reached 63% of a sudden change at the nput (step response). Translated to the VLM500-DG system,
th s means: τ s the length after that 63% of changes n the sk n pass character st cs have been processed by the
nternal processor. Based on th s relat onsh p an appropr ate sett ng of the measurement length (parameter
SYNCLENGTH) can be est mated by d v d ng the des red length by 0.63.
Example: If the user wants to see changes n the sk n pass character st cs after 30m processed length, the sett ng
for SYNCLENGTH should be 30 m: 0.63 = 47.6m approx. 48m.
Attention! The effect of changes n the sk n pass character st c on the mater al s mmed ate.
However, the metrolog cal acqu s t on s delayed.
Calculation of skin pass level and stretching degree
The total lengths L
Master
, L
Slave 1
and L
Slave 2
are used to calculate the sk n-pass or degree of stretch ng. The total length
results from    

 

   

 . The oldest length value from the r ng buffer s subtracted from
the newest measured length value.
All three length values are now used to calculate the sk n-pass or degree of stretch ng us ng the formula:
  

 



 
  

 



 
Where DG s the sk n pass level and RG s the degree of stretch ng.
In th s calculat on DG and RG are referenced to the nfeed of the m ll. See F gure 3.
Figure 3: Position of devices
Relat ons:
v
1
≤ v
2
≤ v
3
and
L
1
≤ L
2
≤ L
3

VLM500-DG User manual General nformat on
page 8 ASTECH GmbH
Whether the calculat on w ll be done w th reference to the n- or outfeed of the mach ne s controlled by the
command SYNCBASIS.
Wh le the commun cat on between the DG-master to the DG-slaves s act ve and the calculat on of the sk n pass
level s runn ng the Busy-LED of the Master l ghts up yellow.
Process monitoring
There s permanent mon tor ng of the commun cat on between the dev ces. If a DG-slave does not send the
requested data to the DG-master w th n 500 ms, an nternal commun cat on error counter s ncremented. If 10
commun cat on errors occur n success on w th a DG-slave, error E70 (for DG slave 1) or error E71 (for DG slave 2)
s output on the DG-master. After that the error counter s reset. The commun cat on error counter s also reset
each t me the commun cat on w th a DG-slave was successful.
The DG master also permanently mon tors the lengths rece ved from the DG-slaves. If length values are not n the
expected nterval of           , error E72/E73 (for DG slave 1) or error E74/E75 (for
DG slave 2) s output on the DG master.
When a commun cat on error occurs or the slave length s out of range, no new calculat on of DG or RG take place.
Instead the last value s output.
If there s a measurement fa lure of the DG-Master, the contents of the r ng buffers are also deleted.
Stop of calculation
In order to end the calculat on of the mass flow values n a targeted manner, the "SYNCSTOP" command has to be
called. Th s s done v a Prof net by sett ng b t 1 n the control byte or by send ng the command to the programm ng
nterface.
In order to restart a calculat on, the "SYNCSTOP" command and then the "SYNCSTART" command must always be
executed. In th s way the contents of the r ng buffers are deleted and the calculat on start restarts aga n.
Start of object movement
Due to ts pr nc ple, a VLM500 cannot acqu re the "standst ll" state of a measurement object. A m n mum speed s
requ red that can be measured by the sensor. It cannot be pred cted at what speed a VLM500 w ll start measur ng.
The m n mum speeds spec f ed n the datasheet are to be understood as guaranteed values from wh ch the
VLM500 can record s gnals n any case. In order to st ll be able to ach eve synchron c ty of the DG master and the
DG slave n the event of a measurement object mov ng from standst ll, the parameter VMIN s used. VMIN s set
the same for all VLM500 dev ces. As soon as the DG master can measure th s speed, t sends a synchron zat on
pulse to the DG slave.

General nformat on VLM500-DG User manual
ASTECH GmbH page 9
Accuracy of measurement
The absolute error of the calculat on of the sk n pass level s equal to the sum of the relat ve errors of the two
measur ng dev ces. In the data sheet of the VLM500, the relat ve error spec f ed under laboratory cond t ons s
g ven as ± 0.025%. Thus, the absolute error of the sk n pass system s ± 0.05%. The measurement curve n the
follow ng f gure shows the spread under laboratory cond t ons. The set sk n pass level s close to zero.
Figure 4: Measurement accuracy under laboratory conditions
The spread s approx mately +/- 0.05%. Th s d str but on would also occur n the case of sk n pass levels dev at ng
from zero. The absolute error rema ns the same.
Under real cond t ons, absolute errors n the sk n pass system of ± 0.2% are to be expected for total lengths of up
to 50 m. Larger sk n pass levels can therefore be acqu red more prec sely than smaller ones because the absolute
error rema ns the same.
-0,1
-0,08
-0,06
-0,04
-0,02
0
0,02
0,04
0,06
0,08
0,1
0 1000 2000 3000 4000 5000 6000
Skin pass level [%]

VLM500-DG User manual Data transm ss on
page 10 ASTECH GmbH
2 Data transmission
2.1 Profinet
The VLM500-DG system can be equ pped w th a Prof net nterface. The assoc ated IFPN nterface card s nstalled
n the DG master and connects t to the network. Th s enables the commun cat on between a PLC and the DG
master over large d stances us ng standard zed network components. The current mass flow measured values can
be output synchronously w th the tr gger. It s also poss ble to send control commands to the master v a Prof net.
A small webserver s also ava lable prov d ng a webs te show ng status nformat on about the measur ng dev ce.
Figure 5: Status page of the integrated webserver
Output mode
The Prof net nterface s conf gured v a the Prof net master (Prof net IO controller). Interface-spec f c parameters
such as the IP address to be used, the subnet mask, the gateway, the name or the mode can be changed.
There are 7 modes for data exchange w th the IO controller (see table 1) ava lable. For correct commun cat on, the
data output mode set n the master must match that n the Prof net IO controller. The data output mode n the
master VLM s set w th the SYNCOUTPUT command. The same mode must be selected n the controller (PLC). The
prov ded GSDML f le supports all 7 modes.