Allen-Bradley 1734-IK/C​ POINT I/O Incremental Encoder/Counter Module – 1MHz High-Speed Quadrature Input

Product Overview

The Allen-Bradley 1734-IK/C​ is a POINT I/O Series Incremental Encoder / High-Speed Counter Module manufactured by Rockwell Automation, designed to provide a compact, distributed interface between incremental quadrature encoders (A, B, and Z channels) or pulse-generating sensors and a Rockwell Automation control system. As a member of the Bulletin 1734 POINT I/O family, the Allen-Bradley 1734-IK/C​ mounts on a standard 1734 POINT I/O rack alongside a POINT I/O adapter (such as the 1734-AENTR Ethernet/IP adapter) and communicates encoder position, direction, velocity, and frequency data directly to a ControlLogix or CompactLogix controller over the backplane.The Allen-Bradley 1734-IK/C​ accepts one differential RS-422 (5 V) quadrature encoder input with A, /A, B, /B, and Z, /Z lines, supporting count rates up to 1.0 MHz in X1 mode and up to 250 kHz in X4 (quadrature ×4) mode. It features a 32-bit signed or unsigned counter register, programmable preset values, and multiple operating modes including position measurement, rate (velocity) measurement, and period/frequency measurement. The module’s Z (marker/index) input can be configured to preset the counter, reset the counter, or capture the current count value into a latch register for homing routines. Onboard digital filtering and debounce settings help reject noise from long encoder cables or electrically noisy environments.In distributed control architectures, the Allen-Bradley 1734-IK/C​ eliminates the need to route high-frequency encoder signals all the way back to a central chassis-mounted high-speed counter card, instead placing the counting intelligence close to the encoder itself and transmitting resolved position or speed data over the industrial network. This reduces wiring cost, improves noise immunity, and simplifies cabinet layout. The “/C” revision designation indicates the latest hardware revision with improved noise immunity and updated componentry compared to earlier revisions (1734-IK, 1734-IK/A, 1734-IK/B). The module is powered from the POINT I/O rack’s 24V DC bus (obtained from the POINT I/O power supply module such as 1734-EP24DC or 1734-EPAC) and draws approximately 90 mA from the 24V DC field power supply.

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Description

 

Technical Specifications

Product Model | 1734-IK/CManufacturer | Rockwell Automation / Allen-BradleyProduct Type | POINT I/O Incremental Encoder / High-Speed Counter ModuleNumber of Encoder Channels | 1 (A, B, Z differential RS-422)Input Signal Type | RS-422 differential (5 V), A, /A, B, /B, Z, /ZMaximum Input Frequency | 1.0 MHz (X1 mode); 250 kHz (X4 mode)Counter Resolution | 32-bit signed or unsigned integerCount Modes Supported | X1 (1×), X2 (2× direction-sensitive), X4 (4× quadrature)Measurement Modes | Position, Rate/Velocity, Period, FrequencyZ (Index) Phase Function | Reset, Preset (load preset value), Capture (latch count on Z transition)Supply Voltage (Field Power) | 24V DC nominal (10–28.8 V DC)Current Draw from 24V DC Field Power | Typ. 90 mA @ 24V DCBackplane Current Draw (from POINTBus) | 5V DC, typ. 60 mAIsolation (Field Side to System Side) | 1250 V AC rms for 1 minuteTermination Type | Spring clamp or screw (depends on terminal base used)Mounting | 35 mm DIN rail via POINT I/O base (e.g., 1734-TB or 1734-TBS)Operating Temperature | -20 °C to +55 °C (-4 °F to 131 °F)Storage Temperature | -40 °C to +85 °CRelative Humidity | 5% to 95% non-condensingDimensions (approx.) | 56 × 12 × 76 mm (2.2 × 0.47 × 3.0 in.)Certifications | UL listed, cULus, CE marked, C-Tick, Ex (some zones with proper barrier)Compatible Adapters | 1734-AENTR, 1734-IB8S, 1734-OB8, etc. on same POINT I/O rack

Main Features and Advantages

High-speed quadrature decoding close to the source: The Allen-Bradley 1734-IK/C​ processes encoder pulses locally at the machine level, decoding X1, X2, and X4 quadrature signals in hardware. By performing the count accumulation at the POINT I/O node rather than relying on the controller scan to catch pulses, it guarantees accurate tallying of high-frequency signals up to 1 MHz. The resolved 32-bit position or scaled velocity value is then passed to the controller over EtherNet/IP, DeviceNet, or ControlNet via the POINT I/O adapter, freeing the PLC from high-speed interrupt servicing and reducing network traffic compared to raw pulse transmission.Flexible Z-phase (index marker) handling: The Allen-Bradley 1734-IK/C​ allows the user to configure the Z input behavior per application need. It can reset the counter to zero on detection of the index pulse (useful for absolute homing), load a programmable preset value (for offset homing), or capture/snapshot the current count into a separate register (for verifying marker position relative to a known home). This flexibility eliminates the need for external home switches or additional ladder logic to emulate index-based homing.Multi-mode measurement in a single module: Beyond simple position counting, the Allen-Bradley 1734-IK/C​ can be configured for rate (velocity) measurement using a selectable time base, period measurement for very low-speed applications, or frequency measurement for tachometer-style feedback. These modes are selected through the module’s configuration tags in Studio 5000 / RSLogix 5000 and require no hardware changes. The ability to switch between position and velocity modes—or to read both simultaneously from different data words—makes the module suitable for servo-axis monitoring, web-line speed feedback, and winder/unwinder diameter calculation.Differential RS-422 input with superior noise immunity: The Allen-Bradley 1734-IK/C​ requires true differential encoder signals (A+/A−, B+/B−, Z+/Z−) at 5 V TTL/RS-422 levels. This differential architecture rejects common-mode noise picked up along encoder cables that may run parallel to VFD power conductors, a common cause of false counts in single-ended (open-collector) interfaces. The module includes programmable digital input filters (glitch filters) that can be set from 0 µs to 65535 µs to further suppress transient spikes.Seamless Rockwell software integration with Add-On Instructions: The Allen-Bradley 1734-IK/C​ is fully supported in Studio 5000 Logix Designer with an Electronic Data Sheet (EDS) for automatic recognition in RSLinx Classic and a pre-built Add-On Instruction (AOI) that maps counter, rate, status, and configuration tags into the controller tag database. This reduces engineering time and minimizes configuration errors. Diagnostic bits indicate loss of encoder power, excessive input frequency, and module communication faults, supporting proactive maintenance programs.Compact POINT I/O footprint with modular expansion: At only 12 mm wide, the Allen-Bradley 1734-IK/C​ consumes minimal DIN-rail space. It can be mixed freely with digital I/O, analog I/O, and specialty modules on the same POINT I/O rack, allowing a custom-tailored I/O assembly that matches the exact machine requirement without paying for unused functionality. The module is hot-swappable (when the POINT I/O rack is so configured) for reduced downtime during replacement.

Contact Us WhatsApp / Wechat：+86 18150087953
Phone：+86 18150087953
Email：sales@cxplcmro.com

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