The provided document is a user manual for the Spectrum Controls 1756-CTR8 Counter Module, also available in a conformally coated version as 1756sc-CTR8K. This module is designed for use within Allen-Bradley ControlLogix 1756 I/O rack systems, reading AC and DC pulse information from external sensors and storing the data for retrieval by ControlLogix processors.

Function Description:

The 1756-CTR8 module is a counter module that processes AC and DC pulse inputs from external sensors. It converts these signals into counter and rate data, presenting them as 32-bit floating-point values. The module supports eight input channels, which can be configured in pairs for different operational modes. It also includes gate inputs, allowing for control over counter operation, such as disabling or enabling counting. Configuration of the module, including input type, counter control, and signal filtering, is done through RSLogix 5000 software. The module supports various operational modes: unidirectional counter (up), bidirectional counter (up/down using two channels), X1 quadrature encoder, and X4 quadrature encoder.

Important Technical Specifications:

Hardware Version: A
Firmware Version: 2.0 or later
Power Consumption:
- Backplane Current: 230 mA at 5 VDC, 75 mA at 24 VDC
- Backplane Power: 3.00 W maximum (0.6 W at 5 VDC, 2.4 W at 24 VDC)
- Maximum Power Dissipation: 4.8 W (all inputs at maximum voltage)
Channels: 8 unidirectional / 4 bidirectional and quadrature
Gates: 8 gate inputs
I/O Chassis Location: Any I/O module slot
Conversion Method: FPGA
Input Filtering: Three user-selectable filters (12 kHz, 25 kHz, debounce)
Calibration: Module does not require calibration
Input Overvoltage Protection: ±50 VDC
Input Overcurrent Protection: Less than 4 mA at 50 VDC
Isolation: 2550 VDC continuous between inputs and chassis ground, and between inputs and backplane.
Operating Temperature: 0 °C to 60 °C (32 °F to 140 °F)
Storage Temperature: -40 °C to 85 °C (-40 °F to 185 °F)
Relative Humidity: 5% to 95% (without condensation)
Input Voltage Ranges:
- AC 50 mVpp: VIL -50 mV, VIH +50 mV
- AC 200 mVpp: VIL -200 mV, VIH +200 mV
- 5 VDC: VIL 1 V, VIH 3.5 V
- 12/24 VDC: VIL 6 VDC, VIH 10.5 VDC
Maximum Common-Mode Voltage (Vmax CE): ±50 VAC rms (AC inputs), ±50 VDC (DC inputs)
Maximum Frequency: 65 kHz for all input ranges
Minimum Duty Cycle: Varies by input range (30 for 5 VDC, 35 for 12 VDC, 25 for 24 VDC)
Maximum Duty Cycle: Varies by input range (60 for 5 VDC, 70 for 12 VDC, 55 for 24 VDC)
Minimum Pulse Width: Varies by input range (4.6 µsec for 5 VDC, 5.4 µsec for 12 VDC, 3.8 µsec for 24 VDC)
Input Impedance: Voltage-dependent, greater than 1 Mohm at 5 V, 24 Kohm typical at 24 V
Capacitance: 600 pF typical
Counter Speed: 0 to 65 kHz Input Frequency 0 to 65 kHz
Counter Gate Input: VIL 1.0 V minimum, VIH 3.5 V maximum, Vmax 30 V
Channel Update Time (with scaling): 13 ms for all 8 channels
Accuracy (Frequency Mode):
- 1 Hz Accuracy (maximum typical): Instant ±0.00 Hz, Average ±0.5 Hz
- 65 kHz Accuracy: Instant ±354 Hz, Average ±1 Hz
- Maximum: Instant ±354 Hz, Average ±2 Hz
Maximum Count Value: 16,777,215
Frequency Mode Max Value: 65,000
Recommended Cable: Shielded twisted pair extension wire, Belden #9501 (or equivalent)
Maximum Wire Size: One 2.1 mm² (16 AWG) wire per terminal
Certifications: CE, UL, cUL approved, ATEX Directive (EN 60079-0, EN 60079-7), UKCA Electromagnetic Compatibility Regulations 2016 (BS EN 61131-2, BS EN 61000-6-4, BS EN 61000-6-2), Low Voltage Directive (EN 61010-2-201). Conformally coated versions meet ANSI/ISA 71.04.2013 G3 Environment standard.

Usage Features:

Removable Terminal Block (RTB): The module uses an RTB (1756-TBCH 36-pin Screw terminal RTB or 1756-TBS6H 36-pin Spring clamp RTB) for field-side wiring connections. The RTB can be keyed to prevent incorrect wiring.
Removal and Insertion Under Power (RIUP): The module supports RIUP, allowing it to be removed and inserted while chassis power is applied, though caution is advised to prevent electrical arcing.
Producer/Consumer Communications: The module intelligently exchanges data with other system devices without being polled.
System Timestamp: Data transfers between the module and its owner-controller within the local chassis are timestamped with a 64-bit system clock.
On-Board Features: Includes custom user scaling, analog and digital filtering, and under/over detection.
RSLogix 5000 Integration: Configured using RSLogix 5000 programming software. An Add-On-Profile (AOP) is available for RSLogix 5000 v15 or later, providing custom configuration screens. For older versions (v14 or earlier), a generic module profile and sample project are used.
Operational Modes:
- Uni-Directional: Increments the counter on the rising edge of every clock pulse. All 8 channels can be configured in this mode.
- Bi-Directional: Uses two input channels; one for counting and the second to determine count direction (0 for increment, 1 for decrement).
- X1 Quadrature Encoder: Requires two input channels (A and B). Count direction is determined by the phase angle between A and B (A leading B increments, B leading A decrements). Increments once per quadrature cycle. Includes Anti-Jitter circuitry.
- X4 Quadrature Encoder: Similar to X1, but counts on both rising and falling edges of inputs A and B, resulting in four increments per quadrature cycle.
Storage Modes (StorageMode[x]): Determines how gate behavior affects counter behavior:
- 0 (No store mode): No gate activity stored.
- 1 (Store and continue mode): Reads and stores the count, then continues counting. Useful for determining material length in cutting operations.
- 2 (Store, wait, and resume mode): Stores the count, waits, and then resumes counting. Useful for accumulating counts even during process stops, like daily production in a filling line.
- 3 (Store and reset, wait, and start mode): Stores the count, resets to zero, waits, and then starts counting. Useful for precise dispensing in bottle-filling lines.
- 4 (Store, reset, and start mode): Stores the count, resets to zero, and then starts counting. Useful for meter proving applications with start/stop triggers.
Input Range Selection: Allows selection of thresholds (AC 50 mVpp, AC 200 mVpp, 5 V, 12/24 V) best suited to the sensor's range.
Scaling Factors (KFactor, RFactor, MFactor):
- KFactor: Scales counter output into useful units (e.g., gallons per minute). Counter value is divided by K factor.
- RFactor: Scales output frequency. Frequency value is divided by R factor.
- MFactor: Used for meter calibration, multiplied by the actual count value.
Signal Filters (SignalFilter[x]): Selects analog and/or digital filters (25 kHz digital, 12 kHz analog, 30 Hz debounce) to improve performance.
Gate Filter (GateFilter[x]): Selects debounce filter for gate input, useful for low-frequency devices like relays or proximity switches.
Rollover/Rollunder Configuration (RollOverTo[x], RollUnderTo[x]): Defines whether the counter rolls over to zero or a preset value when reaching its limit, or rolls under to maximum value or preset when counting down to zero.
Stop on Zero/Limit (Stoponzero[x], Stoponlimit[x]): Configures whether the counter stops at zero when counting down, or stops at the count limit when counting up.
Output Tags: Control counter operations like enabling/disabling, resetting, loading preset values, resetting flags, and inverting count direction.
Input Tags: Provide real-time data such as communication status, current count value, stored value, rate, enable echo, reset status, preset status, new stored data flag, new rate data flag, gate state, counter input state, count direction, limit flag, zero flag, and Coordinated System Time (CST).
Multiple Owners: Input modules can have multiple owners, provided all owners maintain identical configurations. This ensures continued operation and data multicasting even if one owner loses connection.
Listen-Only Mode: Allows other controllers to listen to module data without owning it or providing configuration.

Maintenance Features:

Diagnostic LEDs: The module features OK and CAL LEDs to indicate communication, fault status, and internal diagnostics. Specific blink codes indicate various fault conditions (e.g., EEPROM seed failed, CRC failed, invalid serial number, FPGA configuration fail).
RSLogix 5000 Troubleshooting: Fault conditions are alerted through warning signals on the main screen, fault messages in the status line, notifications in the Tag Editor, and status on the Module Info Page.
Preventive Maintenance:
- Protect circuit boards from dirt, oil, moisture, and airborne contaminants by installing the system in a suitable enclosure and keeping the interior clean.
- Regularly inspect terminal connections for tightness to prevent malfunctions or damage.
Safety Considerations:
- Always ensure incoming power is OFF before inspecting connections.
- Avoid actuating devices in machinery by hand; use a wooden stick.
- Safety circuits should be hard-wired to the master control relay and wired in series.
- In hazardous locations, do not disconnect equipment unless power is off or the area is known to be non-hazardous.
- Turn off power before replacing or wiring modules in hazardous locations.
- The device is intended for use only with Allen-Bradley ControlLogix 1756 I/O.
Technical Assistance: Contact Spectrum Controls Technical Support for assistance and product returns. Approved ESD packaging is required for returns to maintain warranty.

Spectrum Controls 1756-CTR8 - Index

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