Choosing between industrial PCs, SCADA, and edge-control hardware is usually a question of what you already own and what the machine has to do. A complete servo edge position controller may be overkill if you only need to replace a control board inside an existing cabinet; a board may be useless if you have no base system to plug it into. This guide compares four products with listed prices from $99.99 to $779.26: a high-thrust servo edge position control system, two PCB-level control boards, and a SCADA main unit. Use the price bars and decision matrix to match your workload, condition, and communication needs.
At a glance: the EPC-A12 is the only complete edge-control positioning system here, with 1-ton thrust and a 150mm stroke. The Sensaphone SCADA 3000 is the only unit described around remote alarm and data logging. The Apex and ST4504-2 boards are component-level options that assume you have a host assembly.
| Product | Listed price | Price bar |
|---|---|---|
| EPC-A12 High-Speed Servo Edge Position Control System 1-Ton Thrust 150mm Stroke | USD 779.26 | |
| Apex Industrial Tech 31-04115-08 Edge Variants PCB Control Board 30-04376-02 | USD 199.99 | |
| ST4504-2 Industrial Control Board - CE Marked - Gold Edge Connector | USD 99.99 | |
| SENSAPHONE SCADA 3000 FGD-3000 MAIN CONTROL UNIT | USD 450.00 |
EPC-A12 High-Speed Servo Edge Position Control System (USD 779.26)
If the job is keeping opaque web material on track, this TECHTONGDA system is the one complete solution in this group. The listing describes a high-precision analog high-speed servo edge position controller with ultrasonic sensing, a 1-ton thrust, and a 5.9-inch (150mm) stroke. It is aimed at applications such as non-woven fabric, woven bags, paper, and cloth. At the top of the price range, it costs $679.27 more than the lowest-priced board here, so it fits when you need the thrust and stroke in one package rather than a replacement PCB. The condition is listed as new, which helps offset the higher entry point.
Apex Industrial Tech 31-04115-08 Edge Variants PCB Control Board (USD 199.99)
This board is a New - Open box PCB with a clear model number: 31-04115-08 and an alternate part number 30-04376-02. If you maintain Apex Edge Variants equipment, those numbers are your main reference for matching a replacement. It is not a full controller or SCADA base, so the practical value depends on whether it drops into an existing assembly that accepts this specific board. At $199.99, it sits between the $99.99 board and the $450.00 SCADA unit. Use it when you already have the surrounding Edge Variants hardware and just need the board.
ST4504-2 Industrial Control Board (USD 99.99)
For the lowest listed price in this roundup, you get a used industrial control board carrying the ST4504-2 identifier and CE marking. The description points to use in OEM industrial control systems, automation equipment, or legacy machine controllers, with a gold-finger edge connector and multiple integrated circuits. It also notes green jumper wires that indicate field modification or repair, and normal wear consistent with service, so the board is best for someone comfortable working with used components. It is priced at $100.00 less than the Apex board and $350.01 less than the Sensaphone unit, which makes it a sensible candidate when the priority is a low-cost replacement for a legacy system.
SENSAPHONE SCADA 3000 FGD-3000 MAIN CONTROL UNIT (USD 450.00)
The Sensaphone SCADA 3000 is built around remote monitoring and alarm communication. The listing highlights flexible communication options including RS-232 serial, data radio, pager, e-mail, and web-page output, plus Windows-compatible software for programming the unit, retrieving data, analyzing event logs, and printing reports. It is the only product here described as a main control unit for SCADA-style monitoring. The condition is used, and at $450.00 it is $250.01 more than the Apex PCB and $350.01 more than the ST4504-2, but $329.26 below the EPC-A12. Choose it when you need alarm and data logging across multiple communication channels rather than high-thrust edge positioning.
| Product | Listed price | Best for | Keep in mind |
|---|---|---|---|
| EPC-A12 High-Speed Servo Edge Position Control System | USD 779.26 | High-thrust edge position control for opaque web materials | Highest listed price; full servo package |
| Apex Industrial Tech 31-04115-08 Edge Variants PCB Control Board | USD 199.99 | Replacing an Apex Edge Variants PCB board | Component board, not a standalone controller |
| ST4504-2 Industrial Control Board | USD 99.99 | Low-cost legacy control board replacement | Used board with field modification/repair indicators |
| SENSAPHONE SCADA 3000 FGD-3000 | USD 450.00 | Remote alarm, data logging, and multi-channel SCADA communications | Used main unit; not for servo edge positioning |
Final recommendation by use case
- Need an all-in-one edge positioning system that can handle heavy opaque webs: EPC-A12 at $779.26.
- Need a bare control board to match an existing Apex Edge Variants assembly: Apex Industrial Tech 31-04115-08 at $199.99.
- Need a low-priced board for a legacy industrial control setup: ST4504-2 at $99.99.
- Need a SCADA main unit that can report alarms by serial, radio, pager, e-mail, or web: Sensaphone SCADA 3000 at $450.00.
