This document describes the HJ-K series Relay contact output option, a feature designed for VIBRA HJ-K series balances. This option provides relay contact signals corresponding to the judgment results of the balance, allowing for external control and integration into automated systems.
Function Description
The primary function of this option is to output relay contact signals based on the judgment results of the HJ-K balance. These judgment results can classify into a maximum of five ranks (Rank1 to Rank5). In addition to judgment results, the option also provides signals for "On measurement" status and error conditions. These signals are output through a D-type 25-pin connector.
The relay contact outputs are designed to indicate various states:
- Rank Judgment: Separate contacts are provided for each rank (Rank1 to Rank5). For each rank, there are Normally Open (NO) and Normally Closed (NC) contacts, along with a common (COM) terminal. The NO contact closes (ON) when the balance judges the measured value to fall within that specific rank, while the NC contact opens (OFF).
- Error (ERR) Indication: Similar to rank judgments, there are NO, NC, and COM contacts for error conditions. The NO contact closes (ON) when an error is displayed on the balance, and the NC contact opens (OFF).
- "On measurement" Indication: This signal indicates when the displayed value is more than 5 times the readability of the balance. It also has NO, NC, and COM contacts. The NO contact closes (ON) when this condition is met, and the NC contact opens (OFF).
- Buzzer Control: NO and COM contacts are available for buzzer control, allowing an external buzzer to sound when activated.
- External Signal Input: Two input terminals, External signal (+) and External signal (-), are provided for contact output control. This allows an external signal to control the relay outputs.
Important Technical Specifications
- Connector Type: D-SUB25P male connector (view from rear).
- Relay Contact Capacity (Resistive Load):
- AC 125V / 0.5A
- DC 30V / 1A
- Equivalent Circuit to Input: The input circuit incorporates a photo coupler with a forward voltage (VF) of 0.8V to 1.4V and a 100 Ω series resistor.
- Example of Relay Input (Current Control Resistor):
- For 5V external voltage, a 270 Ω resistor is recommended.
- For 12V external voltage, a 1 kΩ resistor is recommended.
- For 24V external voltage, a 2.2 kΩ resistor is recommended.
- ON Period for External Signal: When applying an external signal in a pulse wave, the ON period should be at least 100ms.
- Output Control by External Signal: When controlled by an external signal ([26.r.ac. 2] control), judgment results are output for approximately 200ms after the signal starts.
Usage Features
The HJ-K series Relay contact output option enhances the usability of the balance in several ways:
- Automated Sorting and Classification: By providing distinct signals for different weight ranks, the option facilitates automated sorting and classification processes. For example, a system can be configured to divert items into different bins based on whether they are Rank1 (LO), Rank2 (OK), Rank3 (HI), etc.
- Error Indication: The error output signal allows for immediate notification of balance errors, which can be integrated into a larger control system to halt operations or trigger alarms.
- "On Measurement" Status: The "On measurement" signal can be used to confirm that a stable measurement is being taken, preventing premature actions based on unstable readings.
- External Buzzer Integration: The buzzer output allows for an audible alert to be triggered based on specific judgment results or error conditions, providing immediate feedback to operators.
- External Control of Outputs: The external signal input provides flexibility for controlling the relay outputs from an external source. This is particularly useful for synchronizing the balance's output with other equipment or for implementing specific control logic.
- Configurable Judgment Settings: The balance's limit function settings allow users to define the conditions for judgment, including:
- Limit function effective: Enables or disables the limit function.
- Judgment at all times: Allows judgment even when the balance is unstable.
- Whole range above zero: Defines the range for judgment.
- Number of set points: Configures for 2 points (upper & lower) for HI/OK/Lo judgment.
- Judgment method: Real value.
- Buzzer settings for each rank: Allows enabling/disabling the internal buzzer for each rank.
- HI/OK/LO/rank indication: Controls the display of judgment results.
- Relay output control: Allows output at all times or control by an external signal.
Maintenance Features
While the document primarily focuses on functionality and usage, some aspects relate to proper installation and care, which can be considered maintenance-related:
- Spark-Off Circuit for Inductive Loads: When connecting inductive loads (e.g., relays, solenoids) to the relay contacts, it is crucial to supply a spark-off circuit. This prevents arcing at the contacts, which can degrade their performance and lifespan. The document provides an example of such a circuit using a diode and a resistor.
- Correct Wiring and Resistor Usage: Users are explicitly cautioned to apply the specified current, avoid wrong connections, and use appropriate control resistors for the relay input. Incorrect wiring or excessive current supply can damage the internal circuit of the option.
- AC Adaptor Disconnection: The caution "Always unplug the AC adaptor before connecting" emphasizes a critical safety and maintenance practice to prevent electrical damage during installation or modification of connections.
- Operational Status Monitoring: The "Status of the balance and the contact" table provides a clear guide for troubleshooting by correlating balance display messages (e.g., "No result is displayed," "o-Err/u-Err," "ГМ flickers") with the expected contact output status (e.g., "All OFF," "ON in ERR"). This helps in diagnosing issues related to the balance's operation or the relay output option.
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