Delta DVP PLC — which series fits your application
Delta DVP is a PLC lineup that has held its ground in industrial automation for over 15 years. Four series — SS, SA, SX, SV — cover everything from basic relay control with 14 I/O points to complex multi-axis systems with 16k-step programs. We sell and commission these controllers daily, so we know their strengths and weaknesses from real panel builds, not just datasheets.
Quick summary: SS2 is for simple tasks (conveyors, dosing), SA2 adds analog expansion without extra modules, SX2 has built-in analog right in the housing, and SV2 is for when your program grows and you need speed. Below is a detailed comparison with actual numbers and recommendations.
DVP-SS2 Series: entry level for straightforward tasks
DVP-SS2 is the most affordable Delta controller. Program memory is 8k steps, basic instruction speed is 0.35 μs, and you can expand up to 480 I/O points via extension modules. For "turn on, turn off, count" type tasks — you do not need more.
- Program memory: 8k steps
- Data registers: 5,000 words
- Base I/O: 14 to 32 points (depending on model)
- High-speed counters: 8 points (4×20 kHz + 4×10 kHz)
- Pulse output: 2 points up to 100 kHz (Y0, Y2)
- Communication: RS-232 + RS-485, Modbus ASCII/RTU
In practice, SS2 goes into conveyors, packaging machines, basic pump stations. If you need to control 5-10 discrete outputs with no analog signals — SS2 handles the job at minimum cost. The only limitation: if the project grows, 8k of memory may not be enough, and you will need to upgrade to SV2.
Programming is done in ISPSoft or the older WPLSoft. Supported IEC 61131-3 languages include Ladder Diagram (LD), Function Block Diagram (FBD), and Structured Text (ST). For most automation tasks, LD is sufficient — it is the classic relay logic that even electricians can read without programming experience.
DVP-SA2 Series: expanded capabilities with analog inputs
SA2 is essentially SS2 with more brains. Program memory doubles to 16k steps, there is a left-side expansion connector, and most importantly — direct support for analog modules without intermediate converters.
| Parameter | DVP-SS2 | DVP-SA2 |
|---|---|---|
| Program memory | 8k steps | 16k steps |
| Data registers | 5,000 words | 10,000 words |
| Basic instruction speed | 0.35 μs | 0.35 μs |
| Max I/O points | 492 | 492 |
| Left-side expansion | No | Yes |
| Analog modules | Right side only | Left + right |
When should you pick SA2? When at least one analog signal appears — temperature, pressure, level. SA2 lets you connect sensors with 4-20 mA or 0-10 V output via expansion modules that mount on the left side of the CPU. This saves panel space and simplifies wiring.
We often recommend SA2 for pump station control where you need analog feedback from a pressure sensor alongside discrete signals (dry run, level). Paired with an HMI panel, it becomes a compact monitoring system.
DVP-SX2 Series: built-in analog in a compact package
SX2 is for those who do not want to buy separate analog modules. The base unit includes 2 analog inputs (12-bit) and 2 analog outputs right out of the box. For small systems that need to read a couple of sensors and output a control signal — this is the most cost-effective option.
- Built-in AI: 2 channels, 12-bit, 0-10 V / 4-20 mA
- Built-in AO: 2 channels, 12-bit, 0-10 V / 4-20 mA
- Program memory: 16k steps
- Discrete I/O: 14 points base (8 DI + 4 DO + 2 AI + 2 AO)
A typical scenario is controlling a small servo drive or regulating motor speed through a VFD. SX2 reads the analog signal from a sensor, calculates PID with built-in functions, and outputs an analog signal to a Delta VFD.
The downside of SX2 is limited expandability compared to SA2. If a year from now you need 8 analog channels instead of two, you will have to either buy additional modules or migrate to SA2/SV2.
DVP-SV2 Series: the DVP flagship
SV2 is the most powerful controller in the DVP family. Basic instruction speed is 0.24 μs (versus 0.35 in younger models), program memory is 16k steps, 10,000 data registers, and left-side high-speed parallel expansion.
- Speed: 0.24 μs (basic instructions) — fastest in the lineup
- Pulse output: 4 points up to 200 kHz
- High-speed counters: up to 200 kHz per channel
- Ethernet: optional via module
- Positioning: built-in linear interpolation functions
SV2 is the pick for positioning, high-speed counting, or large programs. If your project requires stepper motor control, Delta servo drives, or complex logic with hundreds of timers — SV2 can handle it. We have installed SV2 on metal cutting lines requiring ±0.01 mm positioning accuracy, and the controller performed well.
Another SV2 advantage is parallel high-speed expansion through the left port. Data exchange with expansion modules runs several times faster than through the standard right port. For time-critical processes, this can be the deciding factor.
Full comparison table: all Delta DVP series
| Specification | SS2 | SA2 | SX2 | SV2 |
|---|---|---|---|---|
| Program memory | 8k | 16k | 16k | 16k |
| Registers | 5,000 | 10,000 | 10,000 | 10,000 |
| Basic instructions | 0.35 μs | 0.35 μs | 0.35 μs | 0.24 μs |
| Max pulse output | 100 kHz | 100 kHz | 100 kHz | 200 kHz |
| Built-in analog | No | No | Yes (2AI+2AO) | No |
| Left-side expansion | No | Yes | No | Yes (fast) |
| RS-232 | 1 | 1 | 1 | 1 |
| RS-485 | 2 | 2 | 2 | 2 |
| Price segment | Budget | Mid-range | Mid-range | Premium |
As you can see, the difference between series is not just price. Each covers its own class of applications. Do not overpay for SV2 if you need basic discrete control. And do not skimp on SS2 if you will be adding analog channels in six months.
Which series to choose: recommendations by task type
- Discrete control up to 32 I/O (conveyor, dosing, barrier gate) → DVP-SS2
- Discrete + 1-4 analog channels (pump station, HVAC, simple PID) → DVP-SA2 or DVP-SX2
- Positioning, high-speed counting (cutting, packaging, CNC-lite) → DVP-SV2
- Compact all-in-one system (small panel, minimal modules) → DVP-SX2
- Large project with expansion potential (production line, workshop) → DVP-SV2 + expansion modules
If you are torn between SA2 and SX2 — the question is scalability. SX2 costs less upfront (analog is already built in), but SA2 gives more flexibility when expanding. For one-off projects — SX2; for systems that will grow — SA2.
Connectivity and communication of Delta DVP PLCs
All DVP series support Modbus ASCII/RTU over RS-232 and RS-485. This means you can link the controller to an HMI panel, VFD, sensors, and other equipment using a standard industrial protocol.
- RS-232 (COM1): programming + HMI connection
- RS-485 (COM2, COM3): Modbus network with multiple devices
- Ethernet: via DVP-EN01-SL module (for SV2/SA2)
A typical architecture: the PLC polls 5-10 sensors over RS-485 and sends commands to Delta VFDs. The operator panel connects via RS-232 or Ethernet. For upper-level SCADA connectivity — an Ethernet module.
For more on communication protocols, see our article on Modbus RTU and TCP: connecting PLCs with equipment.
Frequently Asked Questions
What is the difference between DVP-SS2 and DVP-SV2?
The main differences are speed and expansion capabilities. SV2 executes basic instructions in 0.24 μs (versus 0.35 for SS2), has left-side high-speed expansion, and pulse output up to 200 kHz. SS2 is a budget option for simple discrete tasks.
Can I connect an analog sensor to DVP-SS2?
Yes, via external expansion modules (e.g., DVP-04AD). Modules mount on the right side of the CPU. But if you need analog from the start, it is cheaper to get DVP-SX2 with built-in analog channels.
What programming language should I use for Delta DVP?
ISPSoft supports Ladder Diagram, Function Block Diagram, and Structured Text per IEC 61131-3. For typical automation tasks, most engineers use Ladder Diagram — it is easy to read even for electricians without programming background.
How many devices can I connect via Modbus to Delta DVP?
Up to 254 devices on a single RS-485 bus (Modbus protocol limit). In practice, stable operation holds up to 16-20 devices; beyond that, segment the network or switch to Ethernet.
Is Delta DVP suitable for servo motor control?
DVP-SV2 — yes, it has built-in positioning functions and pulse output up to 200 kHz, which is sufficient for driving Delta ASDA series servo drives. The lower series (SS2, SA2) can also output pulses but are limited to 100 kHz.
Summary
Delta DVP is a proven PLC lineup where each series has a clear specialization. SS2 handles simple discrete tasks, SA2 adds analog module expansion, SX2 is a compact solution with built-in analog, and SV2 tackles complex projects with positioning and high processing speed. Choose based on your actual project requirements rather than "just in case" — it will save both budget and commissioning time.
Browse all available models and prices: Delta PLCs in our catalog. Or compare with Mitsubishi PLCs and Siemens PLCs if you are considering alternatives.
