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GR91 Controller GR 91

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General characteristics

Possible types of regulations: - ON-OFF - Pl (proportional and integral) - PIQ (proportional, integral, and directly proportional to flowrate). The PIQ adjustment represents an important novelty inasmuch as it allows an immediate intervention to be made for the intake of the chemicals upon any change of liquid flowrate, without waiting for the analyzer's return signal. A metering can also be made proportional only to the flowrate (IF). Moreover, by associating the operating threshold with one of the two other thresholds (MAX or MIN), a hysteresis-based ON-OFF type adjustment may be made as well. The proportional parameter "P" may range from 0% fo 400% and the integration time "I" from 1 and 20 minutes. The flowrate parameter "Q" is directly related to the metering level. The regulation is typically performed by using the 4 -:20 mA analog output which governs the self-regulating metering pump (4 mA = 0% flowrate; 20 mA = 100% flowrate), but the ON-OFF output may be used as well, which allows a PWM* to be carried out over a time which is generally of 60 seconds. The calibration of the unit can be performed by entering data relevant to two characteristic points of the measurement range. Should these data be not easily available, the use of an automatic calibration system based on stored-in-memory average parameters would be in order. A little adjustment is also possible upon only one measuring point.

Software Versions and Specifications for
GR 910 GR 911 GR 914 GR 915 GR 916 GR 917 GR 918
Click on the desired item

All the above operations can be easily carried out and verified by using the display-aided push-button panel. The GR 91 is provided with a user-friendly three-key menu, one key being for the operating mode, and the others (+ and -) allowing parameters selection. The RS 232 port (supplied for the whole GR 91 line) is particularly useful for:

  • connecting the unit with a PC for control and operation purposes;
  • connecting the unit with a PC in order to re-program it by means of our dedicated software;
  • connecting the unit with remote control systems via a modem either on a telephone line or wireless.

In short, GR 91, in all its versions, is a unit able to be suitably integrated with small and medium-size metering systems operated by both local and remote control. The following names of versions are composed from the name of the hardware (for example GR 91) and the version of the software (for example 2) to obtain the full name (for example GR 912)

General specifications

  • Inputs / Outputs optoisolated
  • Diaplay LCD alphanumeric, back illumination, 32 character x 2 linees
  • Interface RS 232
  • Power supply: 230V a.c. 50/60Hz (other volatge on request)
  • 2 fuses (on phase and neutral
  • Absorbtion: 10W
  • 4-20 mA input resistence: 50 ohm
  • Max resistence applicable to 4-20 mA inputs: 200 ohm
  • N.O. contacts holder: 24V 1A max
  • Front dimension: 144 x 144 x 140 (depth) mm
  • Weight: 1.2 kg approx.
  • Protection IP 55
  • EMC - EMI cortified for industrial environment.
GR 910 - Software Version 0
Control function: Controller with possible general configuration.
Measurements: Free
Features:
  • Selection of measurements to be displayed (1)
  • Selection of measurement range (1)
  • Possibility of entrerimg temperature-compensing curve of the analysis(1)
Specifications:
  • 3 analog 4-20 mA optoisolated inputs (analysis + temp. + flowrate)
  • 1 analog 4-20 mA optoisolated inputs feedback from self-regulating pump (e.g. PD series pumps with AR optional)
  • 2 analog 4-20 mA output (pump flowrate + analysis)
  • 3 intervention thresholds (operational, alarm for min., alarm for max.)
  • 3 ON-OFF relay outputs (1 for alarm max., 1 for alarm min.+self-regulator failure and 1 for PWM with TPWM = TINT x 2 sec.)
  • RS 232 interface
(1) Parameters factory-preset or programmable throgh RS 232 port by dedicated software.
GR 911 - Software Version 1
Control function: Threshold-operated ON - OFF
Measurements: pH or Redox or Residual chlorine or Conductivity
Specifications:
  • 2 analog 4-20 mA optoisolated inputs (analysis + temp.)
  • 1 analog 4-20 mA output (calibrated analisys)
  • 3 intervention thresholds (operational, alarm for min., alarm for max.)
  • 3 ON-OFF relay outputs (operational, alarm for min., alarm for max.)
  • RS 232 interface
Note: pH and conductivity measuremnets are temperature -compensed.
GR 914 - Software Version 4
Control function: PI or PIQ (directly proportional to flowrate)
Measurements: pH
Specifications:
  • 3 analog 4-20 mA optoisolated inputs (pH +Temp + Flowrate)
  • 1 analog 4-20 mA optoisolated inputs (feedback from self-regulating pump with AR optional)
  • 2 analog 4-20 mA optoisolated output (calibrated analisys + pump flowrate)
  • 2 alarm thresholds (min. and max.)
  • 1 operational threshold (either PI or PIQ)
  • 3 ON-OFF relay outputs (1 for alarm max., 1 for alarm min.+self-regulator failure and 1 for PWM with TPWM = TINT x 2 sec.)
  • RS 232 interface
TPWM = Period of pulse wave modulation
TINT = Integration time parapeter of PI or PIQ settings
GR 915 - Software Version 5
Control function: PI
Measurements: Dissolved oxigen
Specifications:
  • Calibration automatic in atmosphere
  • 2 analog 4-20 mA optoisolated inputs (analysis + temp.)
  • 1 analog 4-20 mA optoisolated inputs (feedback from self-regulating blower)
  • 2 analog 4-20 mA output (blower control + analysis)
  • 3 intervention thresholds (operational, alarm for min., alarm for max.)
  • 3 ON-OFF relay outputs (1 for alarm max., 1 for alarm min.+self-regulator failure and 1 for PWM with TPWM = TINT x 2 sec.)
  • RS 232 interface
GR 916 - Software Version 6
Control function: Controller/Curve-linerizing unit. Particulary useful for channel flowrate measurements (include the counter).
Measurements: Dissolved oxigen
Features:
  • Selection of measurements to be displayed (1)
  • Selection of measurement range (1)
  • Possibility of entrerimg an output versus input curve (1)
  • Possibility of entering a linearized output/input ratio (1)
Specifications:
  • 1 analog 4-20 mA optoisolated inputs (e.g. channel level)
  • 1 analog 4-20 mA optoisolated inputs (feedback from self-regulating pump with AR optional)
  • 2 analog 4-20 mA output (pump flowrate + analysis)
  • 1 intervention thresholds (operational, alarm for min., alarm for max.)
  • 3 ON-OFF relay outputs (1 for alarm max., 1 for alarm min.+self-regulator failure and 1 for PWM with TPWM = 60 sec.)
  • RS 232 interface
(1) Parameters factory-preset or programmable throgh RS 232 port by dedicated software.
GR 917 - Software Version 7
Control function: PI or PIQ (directly proportional to flowrate)
Measurements: Residual chlorine
Specifications:
  • 2 analog 4-20 mA optoisolated inputs (analysis + Flowrate)
  • 1 analog 4-20 mA optoisolated inputs (feedback from self-regulating pump with AR optional)
  • 2 analog 4-20 mA optoisolated output (calibrated analisys + pump flowrate)
  • 2 alarm thresholds (min. and max.)
  • 1 operational threshold (either PI or PIQ)
  • output/input ratio (IF only)
  • 3 ON-OFF relay outputs :1 for alarm max., 1 for alarm min.+self-regulator failure and 1 for PWM with TPWM = 60 sec.)
  • RS 232 interface
Note: TPWM = Period of pulse wave modulation
GR 918 - Software Version 8
Control function: Cumulative measurements
Measurements: Residual chlorine + pH + Redox
Specifications:
  • 4 analog 4-20 mA optoisolated
  • 2 analog 4-20 mA ( chlorine and pH)
  • 2 operational threshold (Chlorine and pH)
  • 4 ON-OFF relay outputs (ph Threshold, Chlorine threshlod, cumulative alarms)
  • RS 232 interface

Download brochure:

GR91Ingl_03.pdf

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