Description
Unboxing & Physical Snapshot
- Manufacturer: Yokogawa Electric Corporation
- Model: YS1700-020/A31
- Product type: Programmable indicating controller in the YS1000 series.
- Configuration decoding:
-2= without hard manual unit;0= basic type;0= 100 VAC / 24 VDC common power;/A31= RS-485 communication supporting PC-link, Modbus, YS protocol, and peer-to-peer communication. - Physical dimensions: 144 × 72 × 250 mm (H × W × D from panel plate).
- Unit weight: 1.6 kg.
- Panel cutout: 137 +2/−0 × 68 +0.7/−0 mm.
- Estimated packed shipping weight: Approximately 2.2–3.0 kg, depending on ESD protection and carton construction; use the actual packed weight for customs documentation.
- Mounting: Indoor panel mounting using upper and lower mounting brackets.
- Terminals: M4 screw terminals for signal, power, and grounding connections.
- What’s in the box: YS1700-020/A31 controller; mounting clamps and standard accessories when supplied with the original unit; communication accessories are lot-dependent.
Product Introduction
Architecture hook: The YS1700-020/A31 is a panel-mounted programmable indicating controller rather than a rack-mounted DCS processor. The basic enclosure occupies a 72 mm-wide panel position, with a 250 mm body depth, while the /A31 option provides the serial communications interface used to exchange controller data with host systems such as CENTUM CS 3000/VP.
The -020/A31 configuration is particularly important for spare-parts control. It does not include the hard manual unit, uses the AC/DC dual-power basic configuration, and has RS-485 communications. The controller provides programmable and function-selection modes, dual-CPU architecture, and nonvolatile memory without a backup battery or capacitor (useful for long-term warehouse preservation).
Core Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Yokogawa |
| Model | YS1700-020/A31 |
| Product family | YS1000 |
| Product type | Programmable indicating controller |
| Configuration | Basic type, without hard manual unit |
| Communication | RS-485 |
| RS-485 protocols | PC-link, Modbus RTU/ASCII, YS protocol, Peer-to-Peer |
| Analog inputs | 5 × 1–5 V DC |
| Analog outputs | 2 × standard main-unit outputs; configuration-dependent |
| Digital I/O | 6 points, shared DI/DO |
| FAIL output | 1 transistor output |
| Control modes | Programmable, single-loop, cascade, selector |
| Program capacity | 1,000 text-program steps / 400 function-block modules |
| Control calculation | IEEE 754 four-byte floating point |
| Power supply | 24 VDC ±10% or 100 VAC ±10%, 50/60 Hz |
| Maximum power consumption | 750 mA DC / 30 VA AC |
| Operating temperature | 0–50 °C |
| Storage/transport temperature | −20–60 °C |
| Operating humidity | 5–90% RH, noncondensing |
| Storage/transport humidity | 5–95% RH, noncondensing |
| Installation altitude | ≤2,000 m |
| Faceplate protection | IP54 for basic type |
| Dimensions | 144 × 72 × 250 mm |
| Weight | 1.6 kg |
| Panel cutout | 137 +2/−0 × 68 +0.7/−0 mm |
| Warm-up time | 1 minute; 3 minutes for direct-input versions |
| LCD replacement period | 8 years |
| Measurement category | O (Other) |
| Overvoltage category | II |
| Pollution degree | 2 |
Yokogawa YS1700-020/A31
The five standard analog inputs are 1–5 V DC, while the optional direct-input functions such as thermocouple, RTD, mV, isolator, transmitter, or frequency input require a different /Axx option; /A31 alone does not add those direct-input functions.
The controller’s stated maximum DC consumption is 750 mA, while the AC version is rated at 30 VA maximum. At 24 VDC, 750 mA corresponds to approximately 18 W at the specified maximum current; use the manufacturer’s rating rather than this arithmetic value for power-supply sizing.
The unit has no battery or backup capacitor for memory retention. That is significant for spare inventory because extended shelf storage does not create the same battery-leak risk found in older controller designs.
Global Compliance & Industry Certifications
For this exact configuration, the certification suffix must be checked separately from /A31.
- CE Mark: Yokogawa identifies CE compliance for the basic type and applicable YS100-compatible configurations. The
/A08frequency-input option is specifically excluded from CE conformity; that exclusion does not apply to the/A31configuration. - IEC/EN 61010: The YS1700 is compliant with IEC/EN 61010-1, IEC/EN 61010-2-201, and IEC/EN 61010-2-030.
- CSA: Applicable CSA safety compliance is documented for qualifying configurations.
- FM nonincendive: Available as the separate
/FMoption, providing Class I, Division 2, Groups A, B, C, D, T4 approval. - CSA nonincendive: Available as the separate
/CSAoption, also covering Class I, Division 2, Groups A, B, C, D, T4. - RoHS: Yokogawa specifies EU RoHS / EN IEC 63000 environmental compliance, with the
/A08option excluded. - EMC: EN 61326 Class A, EN 55011 Class A Group 1, EN 61000-3-2, and EN 61000-3-3 are identified in the manufacturer’s specifications.
- ATEX/IECEx: Do not infer ATEX or IECEx approval from the FM/CSA hazardous-area options. Confirm the required regional certification for the installation.
- Marine approvals: DNV, ABS, or other marine certification must be verified separately if required.
A critical point: YS1700-020/A31 does not contain /FM or /CSA in the stated part number. Therefore, do not enter Class I Division 2 approval into the asset master unless the physical nameplate or Yokogawa documentation confirms that certification option. The manufacturer explicitly treats /FM and /CSA as selectable options.
Verify specific lot certifications with OEM.
Long-Term Storage & Asset Preservation Guide
Keep the controller in its original protective packaging. The LCD face, rear M4 terminals, communication circuitry, and internal electronics should be protected against impact, conductive dust, and uncontrolled ESD exposure.
Control humidity. Yokogawa permits 5–95% RH for transportation/storage with no condensation, but a long-term MRO warehouse should preferably remain well below the upper limit. Keep the controller away from salt spray, corrosive gases, and condensation; Yokogawa specifically prohibits corrosive gases under its normal environmental conditions.
Preserve the configuration identity. Record the complete YS1700-020/A31 designation, serial number, hardware revision, communication settings, and user-program status. The controller uses nonvolatile memory, so no periodic battery replacement is required, but that does not eliminate the need to preserve the application program and parameter baseline.
Physical Installation Prerequisites
- Install by indoor panel mounting, using the supplied upper and lower mounting brackets.
- Provide a panel cutout of 137 +2/−0 × 68 +0.7/−0 mm.
- Allow at least 100 mm above and below the panel for ventilation, as specified by Yokogawa for the basic type.
- Maintain the specified 250 mm instrument depth behind the panel.
- Panel thickness should be 2.3–25 mm.
- Use the specified M4 screw terminals for signal, power, and ground wiring.
- For RS-485, use shielded twisted-pair cable with the manufacturer’s specified conductor range; the published specification identifies 0.5–1.25 mm² (AWG 20–16) and a maximum communication distance of approximately 1,200 m under specified cable conditions.
- The
/A31interface provides SDA, SDB, RDA, RDB, and signal-ground connections; follow the Yokogawa RS-485 wiring topology and termination requirements. - Yokogawa specifies a built-in 120 Ω termination resistor that can be enabled by parameter setting; verify only one appropriate termination arrangement at the communication-line ends.
- For the 24 VDC supply, observe the documented 24–120 VDC operating range for the dual-power model and its polarity-independent DC input.
- Do not remove the internal unit from its case as routine field maintenance. Yokogawa states that safety-compliance testing is required after such work and that removal/reinstallation should be performed by Yokogawa or an authorized technician.
Buyer’s FAQ
Q: What HS tariff code should befor /A31?
A: Do not assign the tariff classification from the model number alone. The controller’s principal function is programmable process/control instrumentation, so the final HS classification should be based on the technical description and destination-country tariff schedule. Have the customs broker validate the code before export.
Q: What should I declare as Country of Origin?
A: Do not use Japan solely because Yokogawa is headquartered there. COO is determined by manufacturing origin for the specific unit. Use the nameplate, OEM origin statement, or supplier Certificate of Origin.
Q: Is the 1.6 kg figure suitable for the commercial invoice?
A: No—not by itself. The 1.6 kg value is the documented controller weight. The commercial invoice and freight booking should use the actual packed gross weight, including ESD packaging, cushioning, carton, and accessories.
Q: Does tact /A31 include the latest firmware?
A: Do not assume it does. Yokogawa’s supports user programs and configurable parameters, so a replacement must be checked against the target controller’s firmware, parameters, and user-program baseline. The YSS1000 Setting Software is used for user-program development and transfer.
Asset-Control Note
/A31 is a clearly identifiable configuration: -2 = no hard manual unit, 0 = basic type, 0 = 100 VAC/24 VDC dual-power supply, and /A31 = RS-485 communications. Do not substitute a with /A32, /A34, /FM, /CSA, or a different -x1x/-x2x configuration without confirming the complete application and certification requirements.
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