Download ISEG Power Supply programming

04/29/17
ISEG Power Supply LabVIEW programming
( Internal repport )
C.Toader 7/14/00
Required Hardware:
-
NT Workstation;
National Instruments PCI-CAN interface;
ISEG/ ECH-208 Crate/ Containing MHCC 64 Can Controller;
ISEG/ EHQFxxx_ Modules.
Required Software
- LabVIEW 5.1 or higher;
- NI-CAN Software for Windows 95/98 and Windows NT version 1.3 or higher
downloadable at
http://digital.ni.com/softlib.nsf/websearch?SearchView&Query=NI-CAN
Control cable:
Max tested length : 25 m Connector type: 9-Pin Sub-D
(Female Connector) <---------------------> (Male connector)
One to one connection
The Pin 5 on the both sides connected to the ground (shield)
CAN-Line-Terminator.
Prior required information:
- ISEG 16-channel High Voltage Power Supply EHQ F005p / Operators
Manual.Vers 2.1 as of 1999-11-05
- Controller Area Network / CAN : Any general introduction. Easy to found at
http://www.can-cia.de/
- NI-CAN User Manual for Windows 95 and Windows NT/ National Instruments
November 1997/ Part Number 321370B-01
http://www.ni.com/pdf/manuals/321370c.pdf
1. ISEG Programming Information
1.1 Data Format
The datagram structure is matched to the message frame of the standard-format
according to CAN specification 2.0A. From the point of view of the CAN protocol a
simple data transmission will be done. This means that the RTR (Remote
Transmission Request) bit is always set to 0.
Remark: Only modules with the same baudrate can be used in the same crate. The
succesfully tested configuration used a baudrate of 100 kb/sec.
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The command datagram (see § 4.4 in ISEG Operators Manual) will be
transferred as data-word with n-bytes length in the data field of the CAN frames
where n depends on the commands specific dimension. The DLC (Data Length Code)
will be set according to this length.
A short explanation of this dataframe format is given below:
S Identifier
O
F
b11…b0
R Reserved
T
R
00
DLC
n=1-8
Data_ID
Data (n-2)
b3…b0
b7…b0
b7…b0
… … CR
C
Ac
k
F.
15b
Identifier Zoom
ID10
0
ID9
0
ID8
A5
ID7
A4
ID6
A3
ID5
A2
ID4
A1
ID3
A0
ID2
…
ID1
…
ID0
Data
DIR
The ID8 to ID3 (or A5..A0) bits are used to address the module 0..64 but in
the case of a single crate only ID5 to ID3 (A2.. A0) are important. ID10,ID9 are 0 and
ID2, ID1 are not used (they can be set 0 as well).
The information for the direction of the data transfer DATA_DIR is written in
the lowest bit ID0 of the CAN identifier. Therefore the controller (Control PC) will
ask for data with DATA_DIR = 1 (read) and will send data with DATA_DIR = 0
(write).
The Front-end device (ISEG module) will answer to the data request with
datagrames having DATA_DIR = 0. There is only one “read” datagram sent on the
CAN network by an ISEG module and this is the registration request message.
The DATA_ID field identify the command and, when this is a single channel
command the address of the channel to operate. The last four bits in the Data_ID are
in the mentioned case used to address the channel 0..15.
The next data fields are containing the arguments of the given command. This
numerical data are often coded on two bytes with a resolution depending on the
maximal value attainable with the respective module (i.e. the voltages, currents,
rampspeeds are module type dependent).
Because a detailed list of the available commands as CAN dataframes is given
in the § 4.3 of ISEG Operators Manual we will give here only some examples on how
you can form some important ones.
1.2 Command examples
A ) SET VOLTAGE 5 V ON THE CHANNEL 0 OF THE MODULE 0
THE MODULE TYPE IS EHQF00p.
Identifier
0
R Reserved
T
R
0 00
DLC
Data_ID
N=1..8
Data (1)
Data (0)
11
1
11110100
10100000
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Explanation: This is a write command ID0=0 addressed to the first module
ID8..ID3=0 so the identifier will be 0. i.e. 1010 + 0000=”set voltage” + ”on the
channel 0”.The resolution of the voltage setting is given by value R= Vmax/50000
and for the EHQF005p this becomes R=0.01. For a 5V tension we have to send a
value of 500 coded on two bytes (16 bit) i.e. 111110100. Because the CAN datafields
are 8 bit long, we will have DLC=3 and three data fields in total: Data_ID, Data(1)
and Data(0).
B) READ SET VOLTAGE ON THE CHANNEL 0 OF THE MODULE 0
THE MODULE TYPE IS EHQF00p.
Identifier
1
R Reserved
T
R
0 00
DLC
N=1..8
Data_ID
1
10100000
C) READ ACTUAL VOLTAGE ON THE CHANNEL 0 OF THE MODULE 0
THE MODULE TYPE IS EHQF00p.
Identifier
1
R Reserved
T
R
0 00
DLC
Data_ID
N=1..8
1
10000000
If the actual tension is 100 V the module answer will be :
Identifier
0
R Reserved
T
R
0 00
DLC
Data_ID
N=1..8
Data (1)
Data (0)
11
100111
10000
10100000
Remark: the SET voltage is applied on the given channel after this is switched
(SET) ON the existing voltage is the value read in the example C).
1.3 Configuration Test
Before any programming activity you have to ensure that the connection is setup correctly and your NI/PCI-Can card can listen and talk to the crate.
The easiest way to do this is to use an interactive program for CAN
monitoring given as an example in the NI-CAN software named Interact.vi. If the
nican13 has been installed properly you will find the useful vi in the …\National
Instruments\LabVIEW\EXAMPLES\nican\. The Interact.vi gives you also the
posibility to transmit or periodically transmit data frames i.e manually form a
command dataframe. Another advantage is that you don’t have to take care of SOF,
CRC or Ack.F. etc.
Step 1) Switch OFF the ISEG crate. Connect the control cable and the
terminator.
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Step 2) RUN the Interact.vi with the settings given in fig. 1. i.e. 100kb
baudrate, CAN1 interface (or according to configuration1) and no periodically
transmit data (the white square is empty).
Step 3) Switch ON the ISEG crate. At the power on each modules will start to
send periodically a registration request. These registration requests should scroll in the
Data Frame Array and you should be able to see and identify them (Data_ID:
11011000).
i.e. a registration request sent by the second module( Log-on front-end device)
Step 4) Write interactively the following command on the CAN net:
i.e. registration accepted for the second module (or Log-on controller).
The second module should stop sending the command you have identified at
the Step 3) and accept other commands. If no valid command is sent during two
minutes the module will disconnect automatically and start to send again the
registration request data frame.
Remark: This was a very difficult step at the first approach because of the
leak in documentation: The default baud rate is set to 125kb from the factory but the
real baud rate is only 121kb because of an inapropriate quartz oscillator. The PEAK
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Your first CAN port can be assigned to the 0 address therefore this should be checked before using
the NI-Config utility.
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CAN test system delivered with the modules system could listen to modules but not our
PCI-CAN card. The adopted solution was to use the test program to set the baud rates
of each module to a value non which coincides with the declared one, 100kb.
2. The SHIPTRAP-ISEG-DRIVER
2.1 Functions and VI’s
Almost all the important commands have been compiled into a device driver
called ISEG.llb. The application example show the use of the most important ones
and the basic steps in programming an ISEG utility.
http://www-wnt.gsi.de/shiptrap/Drivers/ISEG/EXAMPLE1_SET_READ.html
The first operation is to configure then to open a CAN-Network connection
using ISEG_Open_Can.vi
The second operation is to notify the ISEG modules that a controller is active
(register the modules) by a
Log-on controller command written by the
ISEG_LogOn_CONTROLER.vi
The
third
preliminary
operation
to
set
the
ramp
speed.(ISEG_RAMP_SPEED_SET.vi). The default ramp speed is of the order of
10V/s which is too slow for an example application. For ranges and resolution values
please refer to the ISEG Operator Manual (or below to ISEG_DATA2VAL.vi
description.)
Altough all the channels can be switched on and off individually the driver
provides only vi’s which can do this for the entire module. The vi’s in charge with
this are ISEG_MODULE_SET_OFF.vi & ISEG_MODULE_SET_ON.vi.
The setting and reading of the tensions are single channel commands. These
commands are performed by dedicated vi’s ISEG_1CH_SET_V.vi &
ISEG_1CH_READ_V .vi which can be iterativelly called to set or read a module or a
crate. http://www-wnt.gsi.de/shiptrap/Drivers/ISEG/ISEG_1CH_SET_V.html
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Of course the last step of any application is to close the CAN connexion by
ISEG_Close_CAN.vi. If the connexion is not properly closed you have to switch off
and on the ISEG crate again to avoid network errors.
Besides the command vi’s the driver contains some auxiliary ones used to
format dataframes and/or values:
-
ISEG_MOD2AID.vi Converts the module address and the data direction
read/write into a valid arbitration ID.
-
ISEG_SINGLECH_COM.vi This VI is formatting the given command and the
channel number into a valid DATA_ID.(The majority of the single channel
commands form the DATA_ID field as four bits designating the operation to be
performed and the four left as the channel value ( 0..15).)
-
ISEG_VAL2DATA.vi The dataframes to be sent to the modules are module type
dependent and value type dependent. This VI code the value on 16 bit function of
the module and the value types.
-
ISEG_DATA2VAL.vi The read data from the ISEG module is coded on 16 bit
with a resolution of Max_Value/Scalling factor. The scalling factor is 50000 for
tension and ramp speed and 25000 for current. This VI converts the coresponding
data frames into double values.
-
ISEG_DATA_RESOLUTION.vi calculates the data resolution function of the
module type (EHQF005p,EHQF010p..)and the value type (tension, current, ramp
sped).
Remark: All the vi’s and almost all the controls are have standard LabVIEW
help option.
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2.2 Using the EXAMPLE1_SET_READ.vi.
Step 1) Switch ON the ISEG crate;
Step 2) Set the initial values :
CAN Network Interface : Default Value CAN1
Baud Rate: Default Value 100000
Module: Default Value 0
Module Type: Default Value EHQF005_
Channels ON/OFF: Default Value OFF
Step 3) Run the VI.
Step 4) Set ON the channels and modify the tension values.
Remarks : It is highly recommeded to keep the LabVIEW Help window open so you
can read the controls descriptions.
If the obtained values are the double or the triple of the ones you set probably you
have choosen the wrong module type.
You can only change the module number before you start running the VI. But a
modification to include it in the main loop should take you some 30 “.
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