> Introduction
In the numerical control engine bed or other numerical
control equipment, often can use position 传感 part and so on
diffraction grating ruler or encoder, has surveyed the mechanical
movement part since with the proper motion position and the speed
information. Then the diffraction grating ruler or the encoder
survey the value, needs the special receive part to process. The
common encoder outputs the signal is AB (or ABZ) the orthogonal code
signal, therefore codes also is like this for joins the direction
information the symbol stream, simultaneously also aspect and so on
advantageous antijamming processing. Therefore when receives
this signal needs the special decoding connection electric circuit,
the obtained data also will be the proper motion position/positional
information transmits for the processing unit, either (for instance
PCI) transmits through the main line for in the numerical control
equipment central control system, lets the control system the software
and hardware basis measure the actual information and is ideal (logic)
the information to carry on the contrast, then adjusts the movement
part again according to the comparison erroneous result the position
and the speed, either makes other to sever, the switch output movement
achieves the control mechanical movement the goal. Even, comes
through set of complete algorithms information and so on position,
speed, moment of force to bring into line with in the system, makes
real-time feedback processing, this also is the closed loop which we
said (half closed loop) processes, our common algorithm is PID (or PI)
the algorithm. Since like this, quite conveniently to has let
the mechanical device quickly issue, the supple characteristic in the
entire automatic movement. 1 uses CPLD to realize the encoder decoding connection and
the PWM output function
Now in the market condition already had the
special-purpose encoder signal /AB orthogonal code signal decoding
connection chip, mainly was the chip which country and so on Europe
and America provided, for instance product and so on
HCTL-2016/HCTL-2020. But these product performance prices
compared to or quite bad, function insufficiently rich, uses not not
nimbly convenient, is very difficult to suit the general customers the
demand.
But completes the AB orthogonal code signal decoding function
with center scale CPLD the design, has become a choice, adds the CPLD
plasticity, day by day and walks the good natural price compared to
the tendency, this kind of plan has even become the only most superior
choice.
The ordinary circumstances, Altera/Lattice/Xilinx market
condition mainstream CPLD all may satisfy the design the demand, the
logic in the medium scale, approximately 500-1000 great unit, may
complete 1-4 channel to decode the AB orthogonal code signal decoding
function, and may the sur- 1-4 channel PWM occurrence, as well as the
multichannel numeral measures I/O the expansion function. Or
completes 1-4 axis AB to decode the sur- programmable pulse to have
the function.
But must fully use CPLD the resources, and achieved a high
performance, the redundant reliable design, needs the enough technical
force safeguard, like this only then can have Gao Xingjia the ratio
the product appearance.
Shenzhen Si Maidi the science and technology development limited
company official such company, the specialty is engaged in the
movement controls SOPC (namely CPLD, FPGA) the chip level technology
plan and the platform level technology plan development, and promotes
the many patterns movement to the market to control the SOPC chip
product. SM2100 series is 1-4 group ABZ encoder signal decoding
and PWM the output function SOPC product.
Below is 2,100 series functions introductions
1.1 SM2100 characteristic synopsis
SM2100 provided 1-4 channel ABZ to decode, 4 frequency
multiplications, 16 encoders counts the function which the scope and
16 PWM pulse occurred. Meanwhile attached 8 group general input
and 8 group general output in the chip interior. Because the
chip is the SOPC technology plan, therefore also may make the
direction detection according to the customer concrete demand design.
Chart 1 is its function diagram. Under is its performance
index:
The input clock CLK frequency high arrives 80MHz, standard input
frequency 40MHz;
PWM accounts for the spatial ratio adjustment scope 0 ~ 4,095,
frequency control scope 150Hz ~ 150KHz;
16 encoders counters, may reach count the scope are: 1 ~
65,535;
AB inputs may 4 frequency multiplications, AB input inscribes 3
steps numerals low pass filter, the filter band width 4 levels may
move.
Chart 1: SM2100 function diagram
2 SM2100 design application explanation
SM2100 is a SOPC plan, its application characteristic is
similar to common ASIC to be equally convenient, controls the
component connection through 8 CPU connection and the host,
establishes its active status and the function through internal
register.
CPU connection extremely simple:
8 bidirectional data bus bdbs: D0 ~ 7;
7 address buses: A0 ~ 6;
1 piece route selection: CS_n;
1 reads the permission line: RD_n;
1 writes the permission line: WR_n.
Also may according to the user need, provide 16 main lines
connections. Increases except the data bus to 16 ex-roots, other
signals and 8 main lines connections are same.
Under is the main function establishment register introduction.
Through could these registers descriptions, how however see
clearly the SM2100 concrete function using engineers by item and use.
1.3 SM2100 main function principle and application introduction
A, the encoder decoding counts the function
Next chart 2 is the decoding counts the partial
principles:
Chart 2: The decoding counts the partial principles
The SM2100 chip has 1-4 channel 16 ABZ encoder counter.
Through reads takes various channels the counter register (CNT
*) to be allowed to obtain this channel current idea value. Will
count the clear zero register to various channels (CNT * _CLR) to
write the operation this counter register clear zero.
Each counter input end all has 4 doubling circuits and 3 steps
numerals filter circuit. The digital filter band width is
divided 4 grades to be possible to move, respectively is
10M,5M,2.5M,625K, separately may filter on the ABZ signal the width to
be smaller than 300ns, 600ns, 1.2us, the 4.8us disturbance. To
pattern register (MODE) writes the operation to be allowed separately
to establish various channels the filter band width.
In the Z signal rise along, can count the current encoder the
value to lock the existence index register (CNT * _IDX) center,
simultaneously (STATUS) the center correspondence symbolizes the
condition register position 1. The CPU chip may carries on a
zero processing based on the SM2103 condition register and the index
register value. The condition register index flag bit reads the
operation after the condition register automatic clear zero.
B, PWM output
The SM2100 chip has 1-4 channel 16 PWM output.
Uses in has (difference) supplementarily the pulse-duration
modulation signal to have 死区 the control function. May use
for to 3 phases transistors control to complete in the electrical
machinery control the power actuation and 3 inversions functions, also
may or the union low pass filter completes the DA transformation
function.
The PWM output pulse cycle may through toward control register
PWM_TL, PWM_TH read in the data to establish. The effective data
is 16, namely PWM_TL 8 with PWM_TH low 4.
The n channel pulse width may through toward control register
PWM_WnL, PWM_WnH read in the data to establish. The effective
data is 16, namely PWM_WnL 8 with PWM_WnH low 4.
Reads in 1 o'clock toward the PWM_EN register most low position,
enables PWM; Reads in 0 o'clock, forbids the PWM output (to
output 0 levels).
When the PWM pulse width establishment is bigger than the pulse
cycle the establishment value, the output pulse occupies the spatial
ratio maintenance is 100%. C, general IO application
To the SM2100 chip general input output operation,
directly to GPI, the GPO register carries on read-write then.
This function may use for to complete to the system in the
switch quantity control, or is similar in PLC a I/O control.
22,100 applications plans give an example to introduce
2.1 SM2100 chip in movement control card application:
Based on PCI reading card SMP330
The SMP330 card is 32 PCI which designs using SM2103 and
the PCI connection chip main line 3 channels AB decodes counts with
the PWM output card. This card is suitable for the electrical
machinery control, in the numerical control mechanical system position
monitor. It has manifested the above SM2100 series chip all
function characteristics, codes the counter including 3 channels 16
A/B, 3 16 PWM signal output, with the multichannel general digital
input, outputs the channel.
Because is the board card rank product, therefore also made the
system nature electric circuit to recuperate processing. For
example the encoder signal connection uses the difference input
receive, high speed photoelectricity isolation; PWM output after
74LS06 chip OC output; The digital quantity output input all
passes through the photoelectricity isolation, output also increases
the actuation electric current after the Darington tube; In
addition also increased the isolation power source module on the
board, with increases the system the anti-jamming.
Next chart 3 is the SMP330 system function diagram:
The SMP330 card may use many applications domain:
Electrical machinery control, process surveillance, commercial
run control. Concrete including: Copies the number
machine, the survey analysis instrument, the semiautomatic
localization machine, the PC scheme reveals and so on. It may
complete in the system the reading function, also is to the physical
location/speed information survey, but also has using the PWM function
carries on the control to the electrical machinery, simultaneously the
digital GPI/O function also may use for to the system to carry on the
I/O expansion.
For instance copies the number machine. We in the actual
work piece design production, more complex or the irregular work piece
mechanical outlook design quite are difficult to some, simultaneously
also specially consumes the time. In this kind of situation, if
has the actual reference material object, the use copies the number
machine position survey spot to be fast and also fine obtaining to the
material object outer covering physical location information, the
direct use obtains the data restores it "the appearance" to come, then
designed is a fast highly effective imitation. Then this copies
in the number machine equipment the main processing unit to be allowed
to realize using the SMP330 card.
Chart 3: Is the SMP330 system structure diagram
2.2 SM2100 chip in digital servo driver application
Already had a part of customer to realize its servo
driver product using the SM2100 chip plan, took on the speed and the
position connection processing function in the product, as well as
function which produced to the PWM output.
The here take not brushes the direct current numeral servo
driver as an example. Not brushes the direct current machine the
control functional block diagram to be allowed to use chart 4 to
express.
Chart 4: Not brushes the direct current machine the
control diagram
We if carry on the deep step of entire digitization
circuit design to on chart 3 to subdivide, may obtain the following
chart 5 the digital direct current servosystem function diagram:
Chart 5: Digital direct current servosystem diagram
Then, center blue colors frames body are partial in on
chart 5 may use the SM2100 series chip plan to realize, in the
pessimistic frame scope function may use DSP or FPGA realizes, like
this forms an entire numeral servosystem plan. Certainly in this
system, SM2100 only is becomes but the partial functions and the
connection, main body closed loop algorithm processing is in DSP or
the FPGA realization (with FPGA plan realization also is one of
Shenzhen Si Maidi science and technology development limited company's
products, it included 2100, what is main is the new FPGA
characteristic causes to compare the DSP plan to have original
superiority, here no longer gives unnecessary detail).
Inside such plan, unifies SM2100 to realize, the merit is
increases the system reliability, the performance is good.
In summary, a digital direct current servosystem (driver) the
processing partial realizations, was allowed to use DSP to unify a
SM2100 chip to complete. |
