manualshive.com logo in svg

SRS Labs SIM960, Operation And Service Manual

Share
Download
SRS Labs SIM960 Operation And Service Manual Download Page 64

5 – 2

Circuitry

5.1

Circuit Descriptions

The SIM960 consists of three separate printed circuit boards: the
digital board, the front-panel board, and the analog board. The
digital board is directly beneath the left-hand cover (as viewed from
the front of the module).

Pages 1–3 of the schematics correspond to the digital board. Page 4
is the front-panel board, and pages 5–9 are the analog board.

5.1.1

Microcontroller

The SIM960 is controlled by microcontroller U103. It is clocked at
10 MHz by the oscillator built around U102, which will track the
reference

+

REF 10MHZ signal (if present) on JP103.

5.1.2

Front Panel Display

The front panel display is illuminated by successively strobing eight
digital lines from U301. Each strobe line consists of an NPN emitter-
follower (Q301 through Q308) that energizes one seven segment dis-
play chip and a set of eight LEDs in parallel. The eight cathodes from
the segment display are held high or low at U302 based on a pattern
from the controller. Similarly U303 controls the eight lines from the
LED cathodes, using NPN open-collectors (Q309 through Q316) as
output current bu

ff

ers.

5.1.3

Input Amplifier

The

Measure

and

Setpoint

single ended inputs of the SIM960 are

di

ff

erenced to form the error signal,

ε

, with a standard three op-amp

instrumentation amplifier (U512, U513), operating at 9

×

gain. R544,

R549, R553, & R558 are high-stability resistors (0.1 %, 5 ppm

/

◦

C),

used to reduce o

ff

set drift and to improve common mode rejection

(CMRR). R550 is a 10

Ω

trimpot for trimming the CMRR.

Polarity control is implemented at U514, which switches between
gain

+

1

×

and

−

1

×

with U501A.

Next, U505B is a 12-bit multiplying D-to-A converter (DAC), which
together with U504 is used as a vernier attenuator in the error am-
plifier. Finally, there are three inverting amplifiers in series, each of
which may be switched between gain

−

1

×

and some larger gain. The

three amplifier gains (

−

16

×

,

−

4

×

, and

−

2

×

) allow the total amplifier

gain to be switched by factors of two up to approximately 128

×

. The

order of the amplifiers, largest first, is intended to optimize noise
referred to input.

SIM960 Analog PID Controller

Summary of Contents for SIM960

Page 1: ...ms Revision 2 3 October 10 2013 Distribution in the UK Ireland Lambda Photometrics Limited Lambda House Batford Mill Harpenden Herts AL5 5BZ United Kingdom E info lambdaphoto co uk W www lambdaphoto c...

Page 2: ...returned to a Stanford Research Systems authorized service facility Contact Stanford Research Systems or an authorized representative before returning this product for repair Information in this docu...

Page 3: ...ning Basics 2 2 2 2 Ziegler Nichols Tuning 2 5 2 3 Anti Windup and Conditional Integration 2 7 2 4 Bumpless Transfer 2 8 3 Remote Operation 3 1 3 1 Index of Common Commands 3 2 3 2 Alphabetic List of...

Page 4: ...ii Contents SIM960 Analog PID Controller...

Page 5: ...ion of the SIM960 cannot lead to a con sequential failure of any interconnected equipment that could lead to loss of life or limb or property damage The illustrations charts and discussions shown in t...

Page 6: ...ind on SRS Products Symbol Description Alternating current Caution risk of electric shock Frame or chassis terminal Caution refer to accompanying documents Earth ground terminal Battery Fuse On supply...

Page 7: ...is manual are Front panel buttons are set as Button Adjust is shorthand for Adjust Adjust Front panel indicators are set as Overload Remote command names are set as IDN Literal text other than command...

Page 8: ...Hz RTI Output Range 10 10 V Con guration Parameter control Digital Parameter accuracy 1 Stability 200 ppm C Display Resolution 4 digits Inputs Measure BNC 1 M 10 V range Ext Setpoint BNC 1 M 10 V rang...

Page 9: ...1 General 1 2 1 2 Front Panel Operation 1 2 1 2 1 Inputs 1 4 1 2 2 Ramping 1 5 1 2 3 Connections 1 5 1 2 4 Bar displays 1 6 1 2 5 Restoring the default con guration 1 6 1 3 Rear Panel Monitoring 1 7...

Page 10: ...pplications that do not use the I term Mathematically the behavior is Setpoint Measure 1 1 Output P I dt D d dt O set 1 2 where the three terms within the braces and O set can be indepen dently enable...

Page 11: ...ent is indicated by its ash ing brightness Change the digit selection while Shift is high lighted There are two formats for the numeric display Exponential and xed decimal The format used for a partic...

Page 12: ...setpoint can be supplied at the Setpoint BNC input When the internal setpoint is selected the BNC connector is disconnected from the SIM960 circuitry The Output BNC connector can be toggled between PI...

Page 13: ...mp Start Stop again When the setpoint reaches the new pro grammed value the ramp automatically terminates and Internal stops blinking Note SP Ramp has no sign in the numerical display This is be cause...

Page 14: ...ighted LEDs slightly separated roughly tracking the sine wave As the frequency is fur ther increased to well above the decay time inverse the two lighted LEDs no longer decay at all from their peak le...

Page 15: ...SIM960 see Figure 1 2 Figure 1 2 The SIM960 rear panel 1 3 1 Error Monitor The upper BNC connector carries a bu ered copy of the P output of the error ampli er This output is always available even wh...

Page 16: ...speci ed in Table 1 1 Direction Pin Signal Src Dest Description 1 SIGNAL GND MF SIM Ground reference for signal 2 STATUS SIM MF Status service request GND asserted 5 V idle 3 RTS MF SIM HW Handshake 5...

Page 17: ...TXD directly to TD and similarly RTS RTS and CTS CTS In other words a null modem style cable is not needed To interface directly to the DB 9 male DTE RS 232 port typically found on contemporary perso...

Page 18: ...LOW or PARI commands The maximum standard baud rate that the SIM960 supports is 38400 The minimum baud rate is 110 Above 38400 the SIM960 can be set to the following non RS 232 standard baud rates 625...

Page 19: ...anced features of the SIM960 Analog PID Controller In This Chapter 2 1 PID Tuning Basics 2 2 2 2 Ziegler Nichols Tuning 2 5 2 2 1 Open loop tuning 2 5 2 2 2 Closed loop tuning 2 6 2 3 Anti Windup and...

Page 20: ...cient D These signals as well as an O set are combined at a summing junction to produce the controller output see Eqn 1 2 Figure 2 1 shows a schematic representation of the SIM960 controller topology...

Page 21: ...d to the Measure input of the SIM960 a small positive change would cause a negative change to The resulting change at the controller Outputwould also be negative as would be that of the process output...

Page 22: ...utomatic reset for this reason Integral control simply integrates the error signal with respect to time Thus the controller output changes until the error has been reduced to zero near which point the...

Page 23: ...ge in the control signal Call this time t 0 Record the process response in the Measure signal De ne the dimensionless process step response function h t Measure t Measure 0 Observe the point of maximu...

Page 24: ...D mode with I and D both disabled Choose a value for Setpoint around the desired operating point and set P so some small value Slowly increase P until the process starts to oscillate Record this value...

Page 25: ...e are a variety of anti windup strategies to mitigate this e ect A simple way to implement anti windup is to switch o the integrator whenever the output saturates This is not the same as resetting the...

Page 26: ...utput level Were this not the case the integrator output would likely saturate while in manual mode and upon switching to PID Control mode the controller output would suddenly jump Bumpless transfer i...

Page 27: ...Monitor commands 3 14 3 4 6 Display commands 3 16 3 4 7 Serial communication commands 3 17 3 4 8 Status commands 3 17 3 4 9 Interface commands 3 20 3 5 Status Model 3 25 3 5 1 Status Byte SB 3 26 3 5...

Page 28: ...f 3 11 Integral Gain DERV f 3 11 Derivative Gain OFST f 3 11 Output O set Controller Con guration AMAN z 3 12 Output Manual Output PID Control INPT z 3 12 Input Internal External Setpoint SETP f 3 12...

Page 29: ...3 18 Comm Error Status CESE i j 3 19 Comm Error Status Enable INCR i 3 19 Instrument condition register INSR i 3 19 Instrument status register INSE i j 3 19 Instrument status enable register ADSR i 3...

Page 30: ...er ADSR i 3 19 A to D status register AMAN z 3 12 Output Manual Output PID Control APOL z 3 11 Controller Polarity B BAUD i 3 17 Baud Rate C CESE i j 3 19 Comm Error Status Enable CESR i 3 18 Comm Err...

Page 31: ...Measure Input Monitor MOUT f 3 13 Manual Output O OCTL z 3 10 O set ON OFF OFST f 3 11 Output O set OMON i 3 15 Output Monitor P PARI z 3 17 Parity PCTL z 3 10 Proportional action ON OFF PSTA z 3 20 P...

Page 32: ...3 6 Remote Operation TOKN z 3 24 Token Mode U ULIM f 3 13 Upper Output Limit W WAIT i 3 22 Wait SIM960 Analog PID Controller...

Page 33: ...ace in a 32 byte Input Bu er Characters accumulate in the Input Bu er until a command terminator either CR or LF is received at which point the message is parsed and executed Query responses from the...

Page 34: ...send or or as part of the command Multiple parameters are separated by commas Multiple commands may be sent on one command line by separating them with semi colons so long as the Input Bu er does not...

Page 35: ...Each command is provided with a simple example illustrating its usage In these examples all data sent by the host computer to the SIM960 are set as straight teletype font while responses received the...

Page 36: ...es the derivative control term DCTL OFF Example O set ON OFF OCTL z Set query the o set control to z OFF 0 ON 1 When ON the PID Control path includes the constant output o set OCTL Example ON Proporti...

Page 37: ...5 105 INTG Example 1 5E 3 Derivative Gain DERV f Set query the derivative gain to f in V V s DERV may be set with 2 digits of resolution for 10 5 D 10 and with single digit resolution for 10 6 I 9 10...

Page 38: ...e new value The allowed range is 10 000 SETP 10 000 SETP 1 234 Example Internal setpoint ramping ON OFF RAMP z Set query internal setpoint ramping to z OFF 0 ON 1 When ON the changes to the internal s...

Page 39: ...el STRT START Example Manual Output MOUT f Set query the manual output value to f in volts The manual output can be set with millivolt resolution Note that setting MOUT does not modify whether the con...

Page 40: ...es streaming of Setpoint data If i is speci ed then i measurements will be output at a rate of approximately two measurements per second If i is speci ed as 0 then measurements will be output inde nit...

Page 41: ...peci ed then i measurements will be output at a rate of approximately half a second per measurement If i is speci ed as 0 then measurements will be output inde nitely The SOUT command can be used to s...

Page 42: ...4 6 Display commands Select Field DISP z Set query the eld level to be displayed to z Allowed values of z are PRP 0 Proportional gain IGL 1 Integral gain DER 2 Derivative gain OFS 3 Output o set RTE...

Page 43: ...ghout the transaction see the SIM900 manual discussion of the BAUD command for more examples BAUD 38800 Example Flow Control FLOW z Set query ow control to z NONE 0 RTS 1 XON 2 At power on the SIM960...

Page 44: ...RE 5 Example 1 Standard Event Status ESR i Reads the Standard Event Status Register bit i Upon executing ESR the returned bit s of the ESR register are cleared GAIN 0 Example ESR 16 The binary value 1...

Page 45: ...a ect the register INCR Example 16 Instrument status register INSR i Query the instrument status register bit i INSR Example 16 Instrument status enable register INSE i j Set query the instrument sta...

Page 46: ...t to OFF PSTA Example OFF 3 4 9 Interface commands The Interface commands provide control over the interface between the SIM960 and the host computer Reset RST Reset the SIM960 to its default con gura...

Page 47: ...pied to the Output Queue At power on CONS is set to OFF CONS ON Example Identify IDN Read the device identi cation string The identi cation string is formatted as Stanford Research Systems SIM960 s n...

Page 48: ...ow the input bu er of the SIM960 see section 3 3 2 SETP 0 Example RATE 0 1 SETP 1 0 WAIT 5000 SMON 00 483159 Execution Error LEXE Query the last execution error code Valid codes are Value De nition 0...

Page 49: ...ll parameter s 8 Parameter bu er over ow 9 Bad oating point 10 Bad integer 11 Bad integer token 12 Bad token value 13 Bad hex block 14 Unknown token IDN Example LCME 4 The error 4 Illegal set is due t...

Page 50: ...nses to the TOKN query are ON and 0 At power on TOKN is set to OFF TOKN OFF Example Response Termination TERM z Set query the term sequence to z NONE 0 CR 1 LF 2 CRLF 3 LFCR 4 The term sequence is app...

Page 51: ...RSTOP undef undef undef LLIMIT Instrument Status INSE INSR 7 6 5 4 3 2 1 0 INCR Figure 3 1 Status Register Model for the SIM960 Analog PID Con troller There are three categories of registers in the S...

Page 52: ...e Input Bu er is empty and the command parser is idle Can be used to help synchronize SIM960 query responses ESB Event Status Bit Indicates whether one or more of the enabled events in the Standard Ev...

Page 53: ...ommand that was successfully parsed Out of range parameters are an example The error code can be queried with LEXE CME Command Error Indicates a parser detected error The error code can be queried wit...

Page 54: ...ushed and resets the command parser RTSH Unde ned for the SIM960 Command Error Indicates a parser detected error CTSH Unde ned for the SIM960 DCAS Device Clear Indicates the SIM960 received the Devic...

Page 55: ...ed to indicate ramping is presently underway 3 5 8 Instrument Status INSR The Instrument Status Register consists of latching event ags that correspond one to one with the bits of the INCR see above U...

Page 56: ...version Complete Indicates a new conversion result is available for EMON ADOUT Output Monitor Conversion Complete Indicates a new con version result is available for OMON While reading this register w...

Page 57: ...s Chapter 4 1 Getting Ready 4 2 4 2 Performance Tests 4 2 4 2 1 Input Ampli er O set 4 2 4 2 2 A to D Converter test 4 2 4 2 3 Proportional Gain Accuracy 4 3 4 2 4 Derivative Gain Accuracy 4 4 4 2 5 I...

Page 58: ...ld be taken not to constrict the ventillation holes in the SIM900 mainframe It should be located in a room with stable temperature preferably from 65 to 75 degrees F 4 2 Performance Tests The various...

Page 59: ...displayed value is within 10 mV of 8 000 V Now disconnect the Output from the Measure input and ground the Measure input using a BNC grounding cap or 50 Ohm terminator Turn o I control using ICTL OFF...

Page 60: ...rtional gain accuracy test Reset the SIM960 via the remote interface using RST Turn o the P gain control using PCTL OFF Turn on the D control using DCTL ON With the SR785 in swept sine mode and the so...

Page 61: ...03 3 0 kHz 0 8488 5 104 100 kHz 0 6366 5 105 100 kHz 6 366 In each case the frequency response should be within 2 of the programmed gain value 4 2 6 Ramp Rate Accuracy To test the ramp rate wire the S...

Page 62: ...e Output display at each level In each case the output display value should be within 5 mV of the programmed o set 4 2 8 Manual Output Accuracy Reset the SIM960 using RST Select Manual output using AM...

Page 63: ...t schematics are included In This Chapter 5 1 Circuit Descriptions 5 2 5 1 1 Microcontroller 5 2 5 1 2 Front Panel Display 5 2 5 1 3 Input Ampli er 5 2 5 1 4 Proportional Integral Derivative 5 3 5 1 5...

Page 64: ...based on a pattern from the controller Similarly U303 controls the eight lines from the LED cathodes using NPN open collectors Q309 through Q316 as output current bu ers 5 1 3 Input Ampli er The Meas...

Page 65: ...nce zeroing the o set circuit U610 with U611 is equivalent to switching out the o set signal Note that R643 is placed in series with the feedback resistor R615 in order to roughly match the switch res...

Page 66: ...d on to the output connector BNC without large start up transients Until switch U823 closes the SIM960 output is referenced to ground via R863 100k U820A provides a bu ered analog output of the P sign...

Page 67: ...2 S403 S404 S405 2 00053 000 B3F 1052 D426 D447 D463 3 00425 060 RED S406 S407 S408 JP101 1 00302 010 6 PIN DIF CES U101 3 00903 124 MAX6348 JP103 1 00367 040 15 PIN D U102 3 01378 103 74HCU04 JP104 1...

Page 68: ...505 Q802 3 00927 150 MMBT2907A U509 3 01364 120 OPA4277 Q801 3 01421 150 MMBT2222 U514 U512 3 01360 120 OPA228 R502 R507 R542 R547 4 01175 110 4 02K U601 3 01365 122 DG411DY R510 R533 R534 R819 4 0114...

Page 69: ...age SIM960 Analog PID Controller Distribution in the UK Ireland Lambda Photometrics Limited Lambda House Batford Mill Harpenden Herts AL5 5BZ United Kingdom E info lambdaphoto co uk W www lambdaphoto...

Reviews:

No comments

Brands by name

Popular brands

Load more brands