01 · The Eight QuestionsAsk these before you sign anything
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Is the CPU a configuration option on this board, or a different board?
The answer tells you whether the supplier sells one design with options or a family of near-identical designs. Real examples of a single-design matrix: the UT1003AW lists twelve Core Ultra SKUs (135H through 255H) on one 3.5-inch revision; the AD742A offers N100, N305 and N150; the TL500Z3AW covers Celeron 6305U to Core i7-1165G7. Ask for the CPU matrix on the same PCB revision — if each CPU needs its own revision, your spares and qualification multiply.
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Which changes are BOM or order-time choices, and which need a new revision?
BOM-level options are cheap; layout changes are projects. On real sheets you will see both kinds: the PNM-5210 configures its serial ports to 3× RS232 + 2× RS485 by BOM, the ITX660B offers two power specifications (DC 12–24 V & 12 V) at order time, and the TOP800B switches COM1/2 between RS232 and RS485. Ask the supplier to classify every requested change into the two buckets before the quote.
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What exactly changes in the BIOS, and who does it?
Industrial BIOS work is more than a boot logo. It is serial-port mode selection (UT1003AW switches COM1/2 to RS232/RS485/RS422 in BIOS), watchdog defaults (TOP800B spans 0–255 s, FTEQ20A 255 levels), power-on behavior (the HK800CA defaults to AT mode by jumper so it boots on AC restore), and out-of-band management — the i226-LM controller on UT1003AW and the I219 on TL500Z3AW support AMT. Ask who owns the BIOS image, how long a change cycle takes, and whether the custom image is covered by the standard firmware support window.
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What is documented about my exact configuration?
Specification sheets carry revisions for a reason: AD742A is R102, UT100NU is R101, UT1003AW is R100, FTEQ20A is R110, HK800CA is R111. Ask whether the datasheet you receive reflects your configuration — CPU, memory, serial modes, power option — or the base board. A supplier that documents the configured variant saves you the audit work later, and one that cannot identify the revision of the board in your hand will cost you a field mystery.
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What does a sample round look like, and what is the MOQ for a custom build?
Sample MOQ of 1 pc is the industry-friendly norm and GEOLiNK’s default, but for a custom configuration plan for 1–3 units — one on the bench, one in your enclosure, one in transit. Standard-model samples typically leave within 2–5 days; production runs ship in 7–30 days; payment is T/T with L/C for larger orders, FOB Shenzhen. The real question is what the sample proves: ask that the sample carries the final CPU, the final serial mode and the final power option, not the closest stock unit.
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How is the environment qualification proven for a custom configuration?
A custom SKU inherits the base board’s qualification only if the parts changed do not shift it. The base numbers are consistent across the lineup — −20/+60°C operating, −40/+85°C storage on the wide-temp models, rated input classes from DC 9–36 V down to 12 V — but a different CPU or a different power stage should be re-validated, not assumed. Ask what testing the configured variant goes through (burn-in, thermal cycling) and note that compliance documents such as CE/FCC/RoHS are provided on request per project — no sheet should be accepted on a verbal promise.
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How is long-term supply handled, and what happens at component EOL?
Industrial products outlive consumer BOMs. Medical devices alone can spend 1–3 years in certification before the first unit ships, so the board must be orderable years after your launch. Ask about supply intent — GEOLiNK’s is a long-term intent with long-life BIOS support — and, more practically, ask what the supplier does when a CPU or PHY reaches end-of-life: a substitute CPU on the same revision, a documented migration, or a forced redesign. The answer belongs in the contract, not the sales call.
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Who owns the design change, and how are revisions tracked?
The last question is governance. Confirm who holds the design files, who signs off a change that affects the electrical or thermal design, and how the revision number propagates to the silkscreen, the datasheet and the firmware. The revision discipline you saw in question four is the same discipline that will decide whether your fielded units are traceable when a batch-level anomaly appears. A supplier who hesitates here is a supplier you will fight later.
02 · The Option ShelfCustom options you will actually see on GEOLiNK boards
To calibrate what “custom” should cost and take, here are option categories that already exist on the published sheets — each one a real, orderable variant rather than a promise.
