Moduls PC208 pc208i





The controller is intended to manage processes with weight prescription dosing, based on a user-defined algorithm (user programs and prescriptions). The controller can manage other processes in parallel to the dosing process (for example, transport processes).
Technical characteristics:

External dimensions: 144 x 144 x 180mm.
Power supply: from 187 to 242V AC, 50 +/- 2Hz.
– working: from -5 to 40°C;
– storage temperature: -25 to 50°C.
Class of protection: IP20. The controller is intended to be mounted on a panel, providing highest class of protection (at least IP54).

Input for load cells:
– ADC type: sigma-delta modulation, 19 bits resolution (524 288 units);
– measurement: proportional linear;
– range: up to 3.5 mV/V;
– way of load cells connection: six-wired;
– frequency of measurement: 25 or 50Hz (in 40 or 20mS);
– grades of filtration: eligible from the user programs;
– temperature drift:
– zero drift (without zero tracking): up to 2 ppm °C;
– sensitivity drift: up to 1 ppm °C.
– galvanic insulation – not less than 500V DC / pic AC.

Excitation supplies:
– voltage: 5V p/p AC;
– current: up to 70mA (to 70 ohms equivalent resistance of the load cells).

Communication interface:

– RS485 or RS232C (upon request);
– galvanic insulation – not less than 500V DC / pic AC;
– speed: adjustable from 4.8 to 115.2 kbps;
– communication protocols: Modbus RTU, ASCII protocol (not the same as Modbus ASCII);

Discrete inputs:
– up to 48pcs. in modules containing 16 pcs;
– input voltage of activation: from 12 to 30V DC;
– consumed current: up to 10mA on 24V.

Discrete outputs:
– up to 32 ‘open collector’ outputs in modules containing 16 pcs.;
– commutated voltage from 12 to 30V DC;
– current consumption: up to 200mA per output;

Display (LCD – 2×16 characters, Cyrillic alphabetic):
– upper row:
– two grades for showing the current phase of Program A;
– total weight in the scale;
– symbol for not stabilized weight.
– lower row – current information eligible by button:
– number of the running prescription;
– present number of batches (ordered and executed);
– number of the running material dosed and its net weight;
– current number of the portion in the prescription.

– button for resetting;
– 20 functional and digit buttons;

External display: the module is fitted with its own 220V AC power supply and can be mounted at a location remote from the processor module. The purpose of the external display module is indicate the current gross weight the scale measures with bigger and brighter LEDs.

Functional options:

– free selectable (programmable) external unit;
– programmable grades for the shown weight;
– programmable ranges;
– digital setup (reference) of the scale;
– linearization in up to 8 points;
– programmable auto zero-tracking (zero searching);
– execution of 4 user programs in the same time;
– option for a multi-grade prescription dosing of 24 materials in 35 recipes stored in the memory. The recipes (including the consecutiveness of dosing) are set by the user;
– option for dosing with an increasing or decreasing of weight (filling or emptying);
– specific options providing a complete and adequate dosing of the different materials;
– two types of multi-grade digital filters for the measured weight;
– archiving:
– number of the completed prescription;
– number of the completed batches;
– total quantity (for all materials dosed) in tones;
– dosing status;
– time of starting: date, hour, minutes (month is transmitted via the communication interface);
– time of stopping: date, hour, minutes (month is transmitted via the communication interface);
– quantities in tones for materials with numbers from 1 to 24;
– separate counters per material (‘with’ or ‘without’ resetting);

All data and archives of the controller are kept for a period of 5 years minimum without voltage consummation. Reduction in power supply does not lead to collapse in the started process!
Programming equipment for the PC has been designed for the controller under Windows OS. The programming of the user programs is executed via serial interface of the controller. Configuration parameters are programmed as well. Sample user programs could be available in the PC programming equipment.
User programs can be entered via the controller keypad.