The Yokogawa YS170-012 S4, also cataloged as the YS170 Handheld Communicator, operates as a dedicated hardware component for configuration, calibration, and maintenance of field instrumentation within industrial process networks.

Suffix Breakdown & Model Matrix

• YS170: Base model series for portable HART-compatible field communicators.
• 012: Denotes hardware revision and specific firmware support for HART 7 protocol interfacing.
• S4: Represents the physical build standard, including compliance ratings for hazardous area operations.

Hardware Specifications

Hazardous Area Safety and Signal Conditioning

The YS170-012 S4 is engineered with intrinsic safety (Ex i) barrier compatibility, ensuring the device does not provide an ignition source when operating within hazardous atmospheres. The communicator maintains galvanic isolation between the internal logic circuitry and the field connection probes, which prevents voltage surges from propagating back into the device when interfacing with high-energy instrument loops. The HART 7 protocol implementation ensures transparent data exchange with field transmitters, allowing for real-time validation of process variables and instrument diagnostics without disrupting the primary control loop current.

Frequently Asked Questions

Q: Is the YS170-012 S4 compatible with older HART 5 field devices?

A: Yes. The HART 7 implementation includes backward compatibility modes to ensure seamless communication with legacy field instrumentation, provided the device firmware supports standard HART query-response cycles.

Q: How is the battery managed during field use to maintain safety compliance?

A: The device utilizes a sealed, rechargeable battery pack. To maintain safety certification (Class I, Div. 2), battery replacement must only be performed in non-hazardous locations using approved Yokogawa replacement parts.

Field Installation Guidelines

• Connection: Before connecting to a field loop, ensure the device is in the correct operating mode. For 4-20 mA HART loops, ensure the loop impedance is sufficient (typically 250 to 500 Ohm) to allow the HART signal to pass without attenuation.
• Grounding: Always ensure the handheld device and the field instrument share a common signal ground reference when possible. Avoid touching metallic chassis components of powered equipment while using the communicator.
• Handling: Use the provided protective carry case in high-impact areas. Although the device is durable, the LCD screen is sensitive to mechanical pressure and sharp objects.
• Environment: While rated for -20 deg C to 55 deg C, store the unit in a climate-controlled environment when not in active use to extend the service life of the battery and display electronics.