Frequency measurement device MIDAS FMD2

Frequency measurement device MIDAS FMD2

1.1.    Device assignment

MIDAS FMD2 is designed to measure the pulse frequency, calculate the speed of rotation and acceleration of rotation, generate alarm, warning and other signals based on the measured and calculated value processing and transmit received information on the upper level computing device (hereinafter - ULCD). The personal computer, smart controller or another device which satisfies arrangements outlined in this manual.

MIDAS FMD2 primarily intended for use in the electronic part of the steam and hydraulic turbine control and protection systems.

MIDAS FMD2 is interchangeable, restoreable, repairable, four channel and multi-functional product and It refers to the measuring equipment that can be tested, used in stationary conditions of production facilities outside the houses.

MIDAS FMD2 refers to the combined measurement device with galvanic decoupler, which has both digital and discrete outputs.

MIDAS FMD2 manufactured in accordance with technical conditions (hereinafter – TC)  4252-006-27462912-08.

Due to continuous product improvement there may be minor changes to the circuitry and design, which doesn’t affect its functionality and performance specification.

1.2. Features

• Indicators 
  – Four independent channels for frequency measurement;
  – a wide range of measured frequency: from 0.04 to 20000 Hz;
  – a wide range of input signal amplitudes: from 4 to 24 V;
  – input pulse shape independency: rectangular, triangular, sine;
  – the minimum duration of the input pulse of either polarity: 5 ms;
  – fill-in frequency used for high resolution measurement of the input pulse length: 72 MHz;
  – the basic error limits of frequency measurement;
       ±0,001% (reduced, in a range from 0.04 Hz to 100 incl.);
       ±0,002% (relative, in a range from 100 Hz to 1 KHz incl.);
       ±0,01 (relative, in a range from 1 to 3 KHz incl.);
       ±0,02 (relative, in a range from 3 to 10 KHz incl.);
       ±0,06 (relative, in a range from 10 to 20 KHz incl.);
  – the dielectric strength of the galvanic isolation between all channels of measurement, all interfaces RS422 and power supply circuits: 1000 V;
  – power consumption: not more than 10 W; – Operating temperature range: 0 to 60 ° C;
  – small size of module: not more than 109x115x46 mm. ·
  
  
• Application examples:
  – as part of the electronic speed control systems of rotation of steam, gas and hydraulic turbines;
  – as an independent means of 3rd and 4th overspeed protection stages of hydraulic turbines;
  – as part of a fault protection system of steam and gas turbines with four independent frequency measurement channels;
  – as a means of determining the pumped-storage stations rotation direction (pump-turbines);
  – as a control signal generating device in the process of power systems automation (On / off pumps, brakes, drive, etc.);
  – as a channel of pulse frequency measurement in the automatic control systems. 
• Built-in functions: – Various calculation based on measured values of frequency, rotational speed and acceleration for each channel independently;
  – configuring a wide selection of constant settings and range limits for continuous monitoring of 8 measured and calculated values;
  – the forming wide range of digital signals (hereinafter – DS) for each of the 8 controlled variables;
  – Configuring hysteresis during the registration of set point values transitions and ranges of the border separately for each of the 8 controllable variables;
  – configurable functions of motion control “Stop” and “Zero of speed”;
  – configurable function of the critical acceleration calculation for overspeed protection;
  – determining the direction of rotation by frequency phase outpacing of two measurement channels;
  – separate configuration of on and off condition for each output type of “open collector” on any DC. · 
• Output interfaces:
  – Two independent galvanic isolated RS-422 interfaces for communication with ULCD;
  – four fixed exchange rates for each interface separately: 38400, 57600,115200, 230400 bit/s;
  – isolated RS-422 interface for output to sign synthesis indicators CCD CD-RS422-PM-07;
  – 8 built-in discrete outputs with a maximum sustained load current of 0.5 A and voltage up to 30 V

1.3. Specifications Table. 1 
         – MIDAS FMD2 technical characteristics

Group	№	Parameter name	Value	Units
Input interface	1	The number of functionally independent measurement channels	4
	2	Number of measuring inputs for each channel	2
		Low voltage input  L	from 4 to 10	V
		High voltage input H	from 10 to 24	V
	3	Input impedance at least:
		Input L	500	Ohm
		input H	1500	Ohm
	4	Input current no more than:
		Input L	21	mА
		Input H	21	mА
	5	Channel zone-amplitude insensibility  no more than:
		Input L	from 1 to 3	V
		Input  H	from 2 to 4	V
	6	The perceived shape of the input signal:
		Sinwave signal	positive polarity
		Rectangular voltage pulses	positive polarity
		voltage pulses of triangular shape	positive polarity
Metrology	7	The range of measured frequency	from 0,04 to 20000	Hz
	8	Output frequency measurement accuracy no more than:
		reduced, in the range from 0.04 Hz to 100 Hz inclusive	± 0,001	%
		relative, in the frequency range of 100 Hz to 1 kHz inclusive	± 0,002	%
		relative, in the frequency range of 1 kHz to 3kHz inclusive	± 0,01	%
		relative, in the frequency range of 3 kHz to 3kHz inclusive	± 0,02	%
		relative, in the frequency range of 10 kHz to 20 kHz inclusive	± 0,06	%
		The coefficient of thermal drift of the frequency measurement in the temperature range from 0 to 15 ° C and from 25 to 60 ° C, no more than:
		in the frequency range from 0.04 Hz to 100 Hz inclusive	± 0,000033	%/°С
		in the frequency range of 100 Hz to 1 kHz inclusive	± 0,00004	%/°С
		in the frequency range of 1 kHz to 3kHz inclusive	± 0,0002	%/°С
		in the frequency range of 3 kHz to 3kHz inclusive	± 0,0004	%/°С
		in the frequency range of 10 kHz to 20 kHz inclusive	± 0,0012	%/°С
		The minimum duration of the perceived pulse	5	mcsec
		Measuring and calculating cycle:
		when the input signal frequency> 100 Hz	10	msec
	9	when the input signal frequency< 100 Hz	equal to the period of the input signal
		Supply voltage	from 21,6 to 26,4	V
		Power consumption, no more than:	10	Vat
	10	Number of independent interface ports	3
	11	The exchange rate of a number	38400, 57600, 115200, 230400	bit/sec
		Interface specification	8 bits of data, 1 start-bit, 1 stop-bit, no parity
		Protocol Specification	MODBUS RTU
Power supply	12	The number of installed nodes in the network	from 1 to 247
	13	The maximum response time for a request	3	msec
RS422	14	The maximum length of the RS-422 communication line at a speed of:
	15	38400 bit/sec	1200	m
	16	57600 bit/sec	800	m
	17	115200 bit/sec	400	m
	18	230400 bit/sec	200	m
	19	Number of digital outputs	8
	20	The type of digital output	free collector
		Maximum switching current	0,5	А
		DC switching voltage, no more than	30	V
		Binding response to events	free programmable for DS
		Pulse repetition rate	measurand	Hz
Digital outputs	21	Rotational speed Rotational	Calculated  Value	rev/min
	22	Rotational acceleration	Calculated  Value	rev/min/ sec
	23	The presence of lead in phase (the direction of rotation or movement determination)	Digital signal (hereinafter – DS)
	24	Input level high / low	DS
	25	Zero speed	DS
Measurable and calculated value, DS	26	Stop	DS
	27	The presence of a critical acceleration (overspeed protection)	DS
	28	Exceeding  the setting upper warning set point (hereinafter – UWS)  up	DS
	29	Exceeding  the UWS down	DS
	30	Exceeding  the setting lower warning set point (hereinafter – LWS) up	DS
	31	Exceeding the LWS down	DS
	32	Exceeding the upper alarm set point (hereinafter – UAS) up	DS
	33	Exceeding the UAS down	DS
	34	Exceeding the lower alarm set (hereinafter – LAS)  point up	DS
	35	Exceeding the LAS down	DS
	36	Finding the outside warning settings	DS
	37	Finding the outside alarm settings	DS
	38	Being outside of the acceptable settings	DS
	39	Finding under the UWS	DS
	40	Finding over the UWS	DS
	41	Finding under the LWS	DS
	42	Finding over the LWS	DS
	43	Finding under the UAS	DS
	44	Finding over the UAS	DS
	45	Finding under the LAS	DS
	46	Finding over the LAS	DS
	47	Finding under the upper range level (hereinafter – URL)	DS
	48	Finding over the URL	DS
	49	Finding under the lower range level (hereinafter – LRL)	DS
	50	Finding over the LRL	DS
	51	Minimum pulse duration of perceptual module	from 5 to 255	mcsec
	52	Quantity of impulses per one rotation	from 1 to 255
	53	The settings for each channel, for each measured and calculated value:
	54	URL	MAX
	55	UAS	< URL
	56	UWS	< UAS
Configurable  user settings	57	LWS	< UWS
	58	LAS	< LWS
	59	LRL	MIN
		The the hysteresis settings magnitude of DS	> 0
		The setting value of "Zero speed"	from LRL to URL
		Options of overspeed protection:
		Critical time	from 0 to 65535	ms
		Critical speed	from 0 to 65535	rev/min
		Dimensions	109х115х46	mm
	60	Mounting on DIN-rail	there’s
	61	Weight, no more than	350	g
	62	Protection degree of the case in accordance with GOST 14254-96	IP20
		Mechanical stress sustainability group in accordance with GOST 22261-94	5
		Group of climatic conditions in the operation in accordance with GOST 22261-94	3
Design	63	Operating temperature range	from 0 to +60	°С
	64	Storage temperature range	from -40 to +85	°С
	65	Relative humidity range	from 10 to 80	%
	66	The dielectric strength of the insulation between the inputs / interfaces of RS-422, and power, peak value for 60 seconds, at least	1000	V
Reliability	67	Estimated time of mean time to first failure for MIL-HDBK-217F under normal operating conditions, not less than	100000	hours
	668	The average service life, not less than	12	years
EMC	69	Functionality during exposing  of electromagnetic interference	Performance group III of ГОСТ 50746-2000
		The level of the radiated interference	class А of ГОСТ Р 51318.22-99
Certifications	770	Certificate of Compliance organization's QMS(Quality Management System) requirements of ISO 9001: 2008	№Q-15.02.12d
	71	Certificate of compliance with regulatory requirements	РОСС RU.АГ51.Н00029 №0744401
	72	Certificate of type approval of measuring instruments	RU.C.33.022.A №38827
	73	Permission to use	№РРС 00-048064

 

1.4.    Сonstruction

MIDAS FMD2 is a finish twinboard product, which is placed in the PHOENIX Contact ME MAX 45 5-3 case for mounting on mounting rail(DIN –rail). There are 40 screw terminals “for a clip” in the upper part of case for connecting external circuits. Each group is a detachable connection to simplify the installation. These groups allow pre-connect wires to the detachable part or make the connection to directly the module with detachable joins. Each group of terminals provided with a unique mechanical keys which do not allow the installation of the terminal group in the wrong position.

Appearance of MIDAS FMD2 which is mounted on a DIN - rail is show in the figure(Figure 1). Dimensional drawing of MIDAS FMD2 is shown in the figure (Figure 2). Configuration and Description of MIDAS FMD2 terminals shown in the table (Table 2).

Figure 1 - The appearance of MIDAS FMD2. Figure 2 - Overall drawing of MIDAS FMD2.

Table 2 - Configuration and description of MIDAS FMD2 terminals

№ of terminal	Designation	Type	Description
1	F IN 1 H +	Input	Frequency measurement Input 1 Н +
2	F IN 2 H +	Input	Frequency measurement Input 2 Н +
3	F IN 3 H +	Input	Frequency measurement Input 3 Н +
4	F IN 4 H +	Input	Frequency measurement Input 4 Н +
5	DOUT 1	Output	Digital input 1
6	DOUT 2	Output	Digital input 2
7	DOUT 3	Output	Digital input 3
8	DOUT 4	Output	Digital input 4
9	F IN 1 L +	Input	Frequency measurement Input 1 L +
10	F IN 2 L +	Input	Frequency measurement Input 2 L +
11	F IN 3 L +	Input	Frequency measurement Input 3 L +
12	F IN 4 L +	Input	Frequency measurement Input 4 L +
13	DOUT 5	Output	Digital input 5
14	DOUT 6	Output	Digital input 6
15	DOUT 7	Output	Digital input 7
16	DOUT 8	Output	Digital input 8
17	F IN 1 -	Input	Frequency measurement Input 1 -
18	F IN 2 -	Input	Frequency measurement Input 2 -
19	F IN 3 -	Input	Frequency measurement Input 3 -
20	F IN 4 -	Input	Frequency measurement Input 4 -
21	+24VFOUT	Output	Voltage output
22	NC	-	Not used
23	NC	-	Not used
24	-24OUT	Output	Voltage output
25	A1 (RX+)	Input	RS 422 interface №1
26	B1 (RX-)	Input
27	Z1 (TX-)	Output
28	Y1 (TX+)	Output
29	A0 (RX+)	Input	RS 422 interface №0
30	B0 (RX-)	Input
31	Z0 (TX-)	Output
32	Y0 (TX+)	Output
33	NC	-	Not used
34	+24V	Input	Supply voltage
35	-24V	Input	Supply voltage
36	NC	-	Not used
37	A2 (RX+)	Input	RS 422 interface №0
38	B2 (RX-)	Input
39	Z2 (TX-)	Output
40	Y2 (TX+)	Output

 

1.5 Front panel

The upper surface of MIDAS FMD2 is a front panel is divided into two sections. Each section is closed by separate transparent protective plastic cover. The switches on the front panel can be accessed in the open position of the lid, visual inspection of switches regulations and and LEDs emission can be accessed in the close position. The upper surface of MIDAS FMD2 appearance presented under (Figure 3).

The control LEDs are located in both sections of the MIDAS FMD2 front panel. Eight yellow LEDs glow of «DIGITAL OUTPUT» are located in the left section from «1» to «8». These LEDs indicate the ON (active) state of the corresponding digital outputs.

Constant light of «PWR» LED in the right section indicates ON state of MIDAS FMD2. Three yellow LEDs «TX0», «TX1» and «TX2» in the right section indicate issuance of data from MIDAS FMD2 to ULCD by the respective interface.

The rhythmic flashing of green LED «RUN» reports about serviceability and cyclical working of microcomputers MIDAS FMD2 internal program.

In addition to the control LEDs on the MIDAS FMD2 front panel rotary switches are located on the 16th position. There are two groups of two rotary 16-position switches, which are marked «UNIT0» and «UNIT1».  They are intended for installation of the network node number for the corresponding RS422 interfaces. The node number is set in hexadecimal format. For example, to set the decimal number "10" of site it is necessary to set to "0" left switch in the group, and to set the right - in the «A» position. Setting range of the node number in the network is in the limit from 1 to 247. MIDAS FMD2 enters lock mode, when the node number set on the rotary switches. Out of range will occur automatically when you install a valid node number. 

One of the four possible exchange speeds with ULCD is set by rotary switch «SPEED». The exchange takes place via interfaces RS 422.0 b RS422.1. Compliance with the provisions of the exchange rate set by the switches shown in the table (Table 3.3).

Figure 3 - The appearance of the front surface of the MIDAS FMD2

2. Functional structure

Functionally MIDAS FMD2 is based on micro-computers STM32F103VDT. The MIDAS FMD2 structure includes:

• input interface, which ensure the coordination and galvanic isolation of input signals; 
• output interface, which is three independent galvanically isolated from the other circuits of the module bus driver RS422 interface; 
• 8 microcomputer-controlled digital outputs, type of "open collector"; 
• a secondary power source, providing the conversion of the supply voltage to a necessary voltage for MIDAS FMD2.

     3. Ordering Information
MIDAS FMD2 available in the following versions:

• MIDAS FMD2 - powered by a DC supply of 24 V.

The MIDAS FMD2 Package Includes:

• universal frequency meter MIDAS FMD2 - 1 pc .; 
• Passport - 1 pc .; 
• Electronic versions of this operating manual RAKURS.KB2.02.10.00RE with the procedure of checking MIDAS FMD2 and utility software - 1 pcs .; 
• calibration interface cable (RAKURS.KB 2.01.40.00) - 1 pcs .;