Product Overview

The HIMA F 3237 is an 8-fold safety-related input module. This module connects safety-related proximity switches and resistor-wired sensors. The F 3237 works with proximity switches according to DIN 19234 (NAMUR standard). It monitors all input lines for short-circuit and wire break conditions. The module meets requirement class AK 1 through AK 6. Engineers use this module for emergency stop monitoring and position sensing. The automatic self-test runs continuously during operation.

Technical Specifications

Input Characteristics & Switching Points

The HIMA F 3237 has a switching time of approximately 10 ms. The operating points use input current (IE) for signal detection. A 0 signal occurs when IE is between 0.35 mA and 1.2 mA. A 1 signal occurs when IE is between 2.1 mA and 6.0 mA. A wire break is detected when IE falls below 0.28 mA. A short circuit is detected when IE exceeds 6.5 mA. These precise thresholds ensure reliable safety signal detection.

Line Monitoring & Diagnostics

The F 3237 automatically tests the module completely during operation. The main test routines include multiple safety checks. Switch on and switch off capability verifies output drivers. Crosstalk between input circuits is tested by a walking 0 test. The input filters are checked for correct function. The overall module function is verified continuously. Short circuit and wire break conditions are detected on each sensor line. The LEDs are not tested by the automatic routine.

Line Specifications

The maximum line impedance is 50 Ohms according to DIN 19234. The maximum line length reaches 1000 metres with 0.5 mm² conductor diameter. The supply voltage US is 8.2 V for the sensor loop. Each input channel has a shunt resistor R* of 681 Ohms with 1% tolerance. This resistor has a power rating of 0.25 W. The part number for this resistor is 00 0751681 (positions R17 through R24).

Power Requirements

The HIMA F 3237 draws 90 mA from the 5V DC supply. The module draws 170 mA from the 24V DC supply. The space requirement is 4 TE (standard units). This compact size fits in most HIMA rack systems. The module mounts easily next to other I/O cards.

Special Consideration for Non-Standard Sensors

Some proximity switches do not follow the DIN 19234 standard. For example, the NJ 5-30GK-S1N from Pepperl+Fuchs delivers very low current in the non-damped state. This low current affects the line break supervision of the F 3237 module. You can solve this by adding a 47 kOhm resistor in parallel with the sensor. This resistor increases the output current to 170 µA in the non-damped state. There are no safety limitations for this modification. A break of the parallel resistor is signalled like a line break. A real line break is still detected as before.

Software Support

The appertaining software building block is HB-RTE-. Check the operating system description for the current version. This software block configures the F 3237 for your specific application. It handles sensor type selection and line monitoring parameters.

Installation Guide

Follow these steps to install the HIMA F 3237 input module. First, power down the system before inserting the module. Second, insert the module into a free slot in the rack. Push firmly until the connectors engage. Third, secure the module with the top and bottom retaining screws.

Fourth, connect your NAMUR proximity switches to the input terminals. Use shielded twisted pair cables for long runs up to 1000 metres. Fifth, verify the line impedance stays below 50 Ohms per channel. Sixth, for non-standard sensors like NJ 5-30GK-S1N, add a 47 kOhm parallel resistor. Seventh, apply power and monitor the LED indicators. The automatic self-test will start immediately. Eighth, configure the HB-RTE- software block for your sensor types.

Package Contents

• One HIMA F 3237 8-fold input module

• One printed quick start guide

• One anti-static protective bag

Note: Resistors for non-standard sensors are not included. Purchase 47 kOhm resistors separately if needed.

Frequently Asked Questions (FAQ)

1. What safety level does the HIMA F 3237 support?
The F 3237 meets requirement class AK 1 through AK 6. It is safety-related for SIL 3 applications per IEC 61508. The automatic self-test runs continuously during operation.

2. What happens when a wire break occurs on the F 3237?
The F 3237 detects a wire break when input current drops below 0.28 mA. The module signals a fault through the diagnostic system. The safety function responds according to your configured logic.

3. Can I use the F 3237 with Pepperl+Fuchs NJ 5-30GK-S1N sensors?
Yes, but add a 47 kOhm resistor in parallel with the sensor. This raises the non-damped current to 170 µA. The line break supervision will then work correctly with the F 3237.

4. What is the maximum cable length for the F 3237 inputs?
The maximum line length is 1000 metres with 0.5 mm² conductor diameter. The line impedance must stay below 50 Ohms per DIN 19234. Longer cables may cause false wire break detection.

5. Does the F 3237 test its own LEDs?
No, the automatic test routines do not test the LEDs. The LED function is excluded from the self-test. You must visually check LEDs during manual maintenance procedures.