Inferno #03 22 ноября 2002

Diploma - Diploma Alone Coder-a. Development of software for special logic analyzer. Part 3.

     7. Safety and environmental

                Project


       7.1. Analysis of working conditions

          in rooms with PCs


   Subject of this graduation project is a writing program for
microcomputer by using cross-development.
Consequently, it is understood the work of a programmer with PC 
for a long time, and then a permanent job with the finished 
user program - the operator of an ultralight. 

   The complication of working conditions in connection with 
the use of computer technology has high requirements for human 
organism. 

   Workstation computer programmer and the user is a room with 
a PC (computer center), which in most cases used the universal 
personal computer (PC). Currently, the standard is the 
classification of hazardous and hazards according 
GOST12.0.003-74 * . Premises, which is used by the PC to 
have a significant impact on the safety of the user and 
therefore they must comply with SanPiN 2.2.2.542-96 and SNIP 
2.09.04-87 [9].


   Employees are facing the data center to the influence of 
such dangerous and harmful factors, such as: 

 ■ suboptimal microclimatic conditions;
 ■ high level of noise;
 ■ insufficient lighting, etc.


   When you work directly for the operator
computer monitor on his act and such hazards as:

 ■ low-energy X-rays;
 ■ ultraviolet radiation;
 ■ infrared radiation;
 ■ Static electricity;
 ■ alternating electric and magnetic
field.


   The presence of electrical lighting network creates a risk 
of electric tokom.Takzhe manifest some psycho-physical factors: 

 ■ mental strain;
 ■ surge of visual and auditory
analyzers;
 ■ monotony of work;
 ■ emotional overload.


   The impact of these factors
leads to progressive fatigue,
causing a reduction in health
workers' data centers.

   When you work with computers in the computer center there is 
a danger of fire. Hazards of fire: 

 ■ sparks;
 ■ Increased ambient temperature and subjects;
 ■ Reduced oxygen concentration in the
air;
 ■ toxic combustion products.


   The room, which establishes the PC,
shall be equipped with air conditioning for
maintain optimal microclimatic
conditions. But at the same time air conditioning might
create suboptimal conditions for working, for example, noise,
increase or decrease in humidity or
temperature. Requirements for Workplace Air
zone are listed in Table 7.1.1 [11].


                            Table 7.1.1


               Tempera-Relative-rate
Period, the category of relative motion of the tour
 theory, the air moist air

        work ° C, not in the st-m / s

                Safety requirements more,%


       Easy-22Ў24 40Ў60 0.1
Cold-1a (21Ў26) (75)
 LIMITED Easy-21Ў23 40Ў60 0,1 (0,2)

         1b (20Ў24) (75)


       Easy-23Ў25 40Ў60 0,1 (0,2)
Warm 1a (22Ў28)

       Easy-22Ў24 40Ў60 0.2

         1b (21Ў28) (0,1 Ў0, 3)



   The main PC devices, creating
high level of noise, are the cooling fan in the power supply of 
computers and dot matrix printer at work. 

   In industrial premises with PC
Vibration shall not exceed the established
allowable according SanPiN <Residential and
industrial buildings>. Standards acceptable
vibration are shown in Table 7.1.2 [11].


                            Table 7.1.2


                   Valid values
 Srednegeometri-vibration
 cal frequency of vibration of vibration octave bands, faster 
speed 

       Hz

                  m / s ¤ DB m / s ¤ dB


        2 5.3 25 4.5 Ў10 Ў10 79


        4 5.3 25 2.2 Ў10 Ў10 73


        8 5.3 25 1.1 Ў10 Ў10 67


       16 1.0 31 1.1 Ў10 Ў10 67


      31.5 2.1 37 1.1 Ў10 Ў10 67


       63 4.2 43 1.1 Ў10 Ў10 67

Corrected values ​​of 9.3 and 2.0 Ў10 Ў10 30 72
their level, dBW



   The noise level in rooms with broken equipment should not 
exceed 40 dBA, and during the operation - 50 dBA. Relevant

sound pressure levels are determined according to CH 3077-84 
[11] (Table 7.1.3). 


                            Table 7.1.3

 Sound pressure levels, decibel levels

                                  sound

  Mean frequency is equivalent to
       octave bands, Hz valence

                                 levels

    63 250 1000 4000 audio
31.5 125 500 2000 8000 dBA

 - 63 52 45 39 35 32 30 28 40
86 71 61 54 49 45 42 40 38 50



   Achieving the goal - safe operation
PC - requires the definition of maximum permissible levels of 
electromagnetic radiation, providing security at that distance 
from the monitor, which usually peaks the work is a computer 
user. Options Safety performance of the class described

in GOST 50949-96  and GOST R 50948-96 
<Visual display products for individual use. General ergonomics 
and safety requirements>. Standards for levels of electric and 
magnetic Fields describes SanPiN 2.2.2.542-96 (Table 7.1.4) 
[11]. 


                            Table 7.1.4

 Tension AC Acceptable

   electric field to a value
 radius of 50 cm from the screen, no more

      frequency band


       ¡The 5 Hz 2 kHz 25 V / m


      ¡The 2 kHz 400 kHz 2.5 V / m


    Magnetic induction,

      frequency band


       ¡The 5 Hz, 2 kHz, 250 nT


      ¡The 2 kHz, 400 kHz 25 nT

 Surface electrostatic potential of the display 500



   Particular attention should be paid to the monitor 
osveschennosti.Rabota PC is hard visual work, and non-optimal 
lighting can greatly enhance eye fatigue, and prolonged 
exposure to significantly reduce visual acuity. The coefficient 
of natural illumination levels shall comply with the provisions 
of 23.05-95 snip <Natural and artificial lighting>. Artificial

lighting in the room with the PC should perform general system 
of uniform illumination. In accordance with SNIP 23.05-95 
illumination on the table surface in the zone placement of the 
working paper on the system General lighting should be 300Ў500 
lux. Ripple factor should not exceed

5%, which is achieved by using gas-discharge lamps in the HF 
PRA.Yarkost fixtures general lighting in the area of ​​the 
angles of radiation from 50 to 90 ° from the vertical in the 
longitudinal and transverse planes should not be Over 200 cd / 
m ¤. 

   One of the most serious is the danger of electric shock. From
Electrical lighting network feed on all
PC components, as well as established in the data center air 
conditioners, electrical and other equipment. Applicable 
measures and means of electrical must ensure that the 
requirements GOST 12.1.038-82 * defines the maximum

valid values ​​for contact voltage Upd and flowing through the 
human body current Ipd. The values ​​of Upd and Ipd Accidental

mode (eg, for the closure phase network
on the metal case) time-dependent effects of current t. In the 
case of healthy adults with the technical

means of friction at emergency operation
values ​​of Upd and Ipd must comply
specified in Table 7.1.5 Standards for the production of 
electrical [11]. 


                            Table 7.1.5


      Domestic Production
 t, c electrical electrical


       Upd, B Ipd, Upd mA, V Ipd, mA

0.01 ..
.. 0.08 550 650 220 220
 0,1 340 400 200 200
 0,2 160 190 100 100
 0.4 120 140 55 55
 0.5 105 125 50 50
 0.6 95 105 40 40
 0.7 85 90 35 35
 0.8 75 75 30 30
 1.0 60 50 25 25
Over
 1,0 20 6 12 12



   Risk of electric shock
largely depends on operating conditions
equipment, describing the premises. For
achieve an acceptable level of electrical safety requires that 
in a room with PC no conditions that create, according to the 
Rules for Electrical and GOST 12.1.019-79 *, enhanced or special

Hazards:

 ■ humidity (relative humidity exceeds 75%);
 ■ high air temperature, continuously or intermittently (more 
than 1 day) exceeding +35 ° C;  ■ conductive (non-insulating 
coating) sex;  ■ conductive dust;

 ■ reactive or organic
environment (aggressive couples, sediment, or mold, destroying 
insulation and conductive part);

 ■ ability to simultaneously touch the person to have a 
connection to the land metal structures of buildings, machinery 
and etc. and metallic elements (enclosures,

grounding terminal or vanishing, jacks)
electrical equipment that may be
energized when the damaged working
isolation.


   Measure of protection against electric
shock:

 ■ double insulated electrical installations -
a collection of work (basic) and protective (additional) 
insulation, which are available at a touch electrical parts do 
not acquire a dangerous voltage is damaged only a protective or 
Working isolation;  ■ Reinforced insulation - it's better to

to ensure human safety
operational insulation elements under
voltage equivalent to double insulation
the degree of reliability (protection);
 ■ neutral - it is a deliberate connection of metallic parts of 
electrical installations (buildings), which may be under 
voltage for insulation damage, with earthed neutral source with 
protective earth conductor;  ■ Safety off - it's a fast 
defense, the automatic shutdown of electrical installations in 
the event there danger of electric shock, human [11]. 


   Fire hazard areas with a PC is determined by the 
peculiarities of running into them processes, properties of 
substances and materials used, as well as conditions of their 
treatment. By explosion and Fire safety facilities are 
classified in categories A, B, V1ЎV4, G and D. The premises 
with PC often belong to the category B. 

   Fire hazard areas depends on
the magnitude of his fire on the load Q (MJ)
which includes various combinations (mixture) and hard 
combustible liquids, solids and materials: 


                  N

              Q = ∙ G · Q,

                 i = 1 i Hi

where G - the number of i-th material fire

     i
load, kg;

  Q - lower heating value of the i-th material
   Hi
rial, MJ / kg.

   Definition of fire-category room (V1ЎV4) by comparing the 
maximum value of the specific fire load space with the value of 
g specific fire load ∈ H, given

Table 7.1.6 [11].


                            Table 7.1.6

 Category B1 B2 B3 B4
 premises

 g, MJ / m ¤ More 1401Ў 181Ў 1Ў

  n 2200 Ў2200 Ў1400 Ў180



   Specific fire load ∈ H is determined from the relation: g = 
Q / S, where S - 

                         n
footprint of fire load, m ¤.


   Considered the room has an area of
40 m ¤. Paul it is covered with thick planks
1.5 cm, placed in a room 8 wooden tables weighing 35 kg, wooden 
cabinet weighing 200 kg and 2 wooden partitions

weighing 50 kg. Thus, we obtain:

   Weight parquet: 40.520.0, 015 = 312 kg.

   Weight of wooden furniture: 8.35 200 2 × 50 =
= 580 kg.

   Lower heating value of wood is
12.4 MJ / kg. Specific fire load
premises is:


      (312 580) · 12.4

   Q = = 276,52 MJ / m ¤.

             40


   The room is classified as fire B3.


   For the primary means of fire fighting
rooms with PCs include a variety of carbon dioxide, aerosol, 
powder extinguishers are designed to extinguish fires and fires 
in the early stages of their development. 



  7.2. Selecting the method of conditioning

            room with PC


   Features of operation of electronic
equipment (including PCs) require
the use of advanced heating,
ventilation and air conditioning.
The most difficult room in terms of
implementing the necessary microclimatic
parameters that provide comfortable conditions for staff, a 
computer room. Indoor climate is a combination of temperature, 
humidity and velocity motion vozduha.Soglasno GOST 12.1.005-88

work at the computer center requires
energy up to 139 watts, that allows us to assign it to category 
1a light physical works, and for warm season

is optimal temperature
23Ў25 ° C at a relative humidity 40Ў60%
and air speed up to 0,1 m / sec.

   Technical requirements for the parameters of the 
microclimate in the areas of PC are less stringent, and as a 
settlement can be used by the optimal microclimate parameters 
in the workplace. 



     Outside ∈ H

       air

                  PC PC>

  tn

     > Tvn

              tc>

                >>>

         BC


                 PC PC PC



   Depending on the parameters and types of computers use 
different conditioning circuits and types of air conditioners. 
For areas that contain Computers may be used for household 
air-conditioners installed in the windows and feed the 
processed outdoor air directly into computer room data center. 
Scheme air conditioning with air-conditioning of this type is 
shown in figure 7.2.1 [9].


   We perform an approximate calculation of the required number 
of air conditioners that are required to implement the chosen 
scheme of air, which is used for PC and SM computers. 


                            Table 7.2.1

      Characteristics of air conditioners

        Computer and computer rooms

Characteristics of the KTA KTA KTA BK BK BKristiki 1-10 1-25 
1-8 1500 2000 2500 

Dietel produ-4 6,3 x 2x
sequence of 10 3 3 400 500 630
Air, x10 x10

  3
 m / h

Produ tivity of 46.5 29 9.9 1.74 2.3 2.9
 cold,

  kW



   Type to use air conditioner: BC-1500

   His performance:

                       3
 ■ By Air: G. = 400 m / h;
 ■ in the cold: Q. = 1.74 kW.


   Determine the total power Qevm, which consists of power 
released Computers, electrical appliances, as well as from the 
heat man of 75 Tues


   One PC with a printer allocates 200 watts.
In the computer center are 5
PC, 12 fluorescent bulbs 60 watts each. Thus, the total heat 
dissipation is: 


    Q = N q + N q + N q =

     COMPUTER COMPUTER COMPUTER Chel Chel LL


     = 5.200 8 75 12 · · 60 = 2.32 kW.


   Microclimate parameters inside the building
- Tvn temperature and humidity WHF
determined according to GOST 12.1.005-88 <General
hygiene requirements for working zone air>. For warm
, these parameters are determined by category 1a light physical 
work and comply with: 


      t = 23 .. 25 ° C, r = 40 .. 60%.

       any any


   Calculating the number of air conditioners is calculated as 
follows: 


                 3600 · Q

                       Computer

     N ¢,

                           3600 · Q

                                 to

         1,2 G C · (t-t +)

             to any any n 1,2 G C

                               to Mr.
where the feminine and CH - heat capacity of chilled
air-conditioning and outdoor air, respectively.

   Heat of air is determined by
formula:

                 1,8 d 623fR

       C = 1,005 +; d =;

                 1000 B- Qk.tabl, the estimated number of air-conditioners 
increase is not required. 

   Total air flow through the air conditioner
determined by the formula:


         G = G (1 + Z) (kg / h)

          Mr. Computer

where Z - health factor, Z = 0,1 Ў0, 2 =
= 0.15.


     3600 · Q

           PC 3600.2, 32
G = = = 573,63 kg / h;
Computer C (t-t) 1,04 · (24-10)

        any given


   G = 573,63 · (1 0.15) = 695.67 kg / h.

    n


   The minimum required amount of outdoor air supplied to the 
premises shall not be less than the required sanitary standards 
for submission to one cheloveka.V comfortable air-conditioning 
systems use sanitary norms feed outside air per person shall be 
30 kg / h. Then, for the premises: 


    G = 30N = 30.8 = 240 kg / h.

     n.min Chel

Since ∈ H> Gn.min, the estimated number of air-conditioners 
increase is not required. 

   Thus, the calculation shows that for
the effective maintenance of microclimate parameters inside the 
data center out of five jobs is necessary to use two air 
conditioners BC-1500. This amount of air conditioning provides 
the necessary performance for air and cold.




             8. Conclusion


   The developed software
to manage the specialized logic analyzer will greatly simplify 
the process of setting devices connected to a common bus, at 
the stage of control after production and also in the process 
of setting and operation. The use of this software will 
significantly reduce the time spent on commissioning of the 
equipment. 

   In the capstone project shows the functional diagram of the 
device and describe the control algorithms specialized logic 
analyzer; on these algorithms, a program with given functions 
and parameters. 

   To improve the performance of the system developed and 
implemented a special method of compression of transmitted 
data, focused on the use of a system of required performance 
and optimized to compress digital signals.


   The complexity of the development of significantly
reduced through the use of cross-protection
Programming Asm51Edit 2 and monitoraotladchika Debugger-51. The 
results of debugging programs in the form of graphs and dump 
signals before and after the issue of data kompressiey.Dlya 
simplify the process of generating test sequences of signals as 
well as verification of the returned signal with the original, 
in Delphi 5 has been developed A special program generator with 
built-in decompressor blocks of data response messages ALS. 



             9. Literature

1. Boborykin AV etc. Single chip microcomputers: a guide .- M.: 
, 1994 .- 400 with.

2. Stashin VV, Urusov AV Mologontseva
O.. Design of Digital Devices
on-chip microcontrollers. -
MM: <Energoatomizdat>, 1990. - 224.
3. Brodin, VB, Shagurin II microcontrollers. Architecture, 
programming, interface .- M.: <ECOM>, 1999 .- 400 sec. 4. 
Timothy Bell, Ian H. Witter, John G. Cleary. Modeling for text 
compression.ACM Computer Surveys. Vol. 21, No.4 (Dec. 1989), 
pp.557-591. 5. GP Bogdanov and dr.Metrologicheskoe provision 
and operation of the measuring technique. Ed. VA Kuznetsov .- 
M.: <Radio and communication>.

6. VI Pustovarov. Assembler: programming and analysis of the 
correctness of computer programs .- Kiev.: , 2000 .- 480 
sec. 7. K. Brindley. Electronic instrumentation. Trans. from 
English. YF Arhiptseva. Ed. AP Fomin. - M.:

<Energoatomizdat>, 1989 .- 126 sec.
8. Safety and environmental project:
methodological instructions for undergraduates.
Comp. V. Zaitsev .- Ryazan, RGRTA, 1995 .- 12
with.
9. Air conditioning in data centers: guidelines to the diploma
design. Sost.V. I. Kremnev, NI
Fedotov .- Ryazan, RRTI, 1990. - 8.
10. Control of noise in data centers: guidelines to the diploma
проектированию.Сост.Н.И.Федотов .- Ryazan
RRTI, 1989 .- 11 p..
11. Securing User
when working with PC.: Tutorial. Comp.
UV Zaitsev, VI .- Kremnev, Ryazan, RGRTA,
2000 .- 75 sec.
12. Economic issues of design.
Calculations of economic efficiency in the diploma projects: 
guidelines diploma in engineering. Comp. EV

Misnik, N. Prudnikov. - Ryazan, RGRTA,
2000 .- 16.
13. Typical standard time for programming problems for 
computers.: Ed. M. Chinyakova .- M.: <Economy>, 1989 .- 125 sec.

14. Feasibility study of the graduation projects.: Under red.V. 
K. Bekleshova. - M.: <High School> 1991. - 176.

15. E. Povalyaev. Archivers. - ComputerPress 2'2002.
16. Control program logic analyzer MWI on the PC. Terms of 
Reference. - Ryazan, Federal State Unitary Enterprise RKB 
<Globe>, 2000. 17. C. Teixeira, C. Pacheco. Delphi 5. Guide 
razrabotchika.2 ie: Per.s angl.M.: Publishing House <Williams>, 
2001 .- 1824 with.

18. B. Hoffmann, A. Homonenko. Delphi 5 .- SPb.:
, 2000. - 800.



             10. Applications

Appendix 1. List of abbreviations and conventional
notation


  ■ Akian - kontrolnoispytatelnaya automated equipment;

  ■ AC - an automated system;

  ■ BSA - the flow-chart;

  ■ DOSE - dual-port RAM;

  ■ DOS - Disk Operating System;

  ■ DS - decoder;

  ■ CPC - the operation code;

  ■ LA - logic analyzer;

  ■ MMI - intermodule interface;

  ■ MC - machine cycle;

  ■ RAM - random access memory;

  ■ OMEVM - single-chip microcomputer;

  ■ OS - return message;

  ■ OEVM - single chip computer;

  ■ ROM - read only memory;

  ■ software - software;

  ■ EPROM - EPROM;

  ■ POOL - PC control software logic analyzer;

  ■ PC - personal computer;

  ■ RON - general purpose registers;

  ■ WP - Working Draft;

  ■ EMR - electronic equipment;

  ■ CAD - computer-aided
design;

  ■ SC - Synchronize combination;

  ■ ALS - a specialized logic
analyzer;

  ■ SMC - self-control;

  ■ TOR - Terms of Reference;

  ■ TA - Technical Project;

  ■ TS - Schmitt trigger;

  ■ SHA - address bus;

  ■ SM - Data Bus;

  ■ computer - electronic computer;

  ■ EP - conceptual design;

  ■ MCS-51 - a family of microcontrollers,
includes chip AT89C52;

  ■ RG - register;

  ■ RLE - Run Length Encoding (encoding
length of the repeats);

  ■ SFR - Special Function Registers (registers, special 
functions). 



[Prim.izdateley: Annex 2 and 3, as well as
graphic material sm.v disk archive]