Omron CJ1W-II101 — I/O Interface Unit, CJ Expansion Rack
SKU: CJ1W-II101USD 49.00
CJ-series I/O Interface Unit for expansion rack; pairs with CJ1W-IC101 via CS1W-CN@@3 cable. Mounts immediately right of expansion rack power supply. 31 mm wide, no settings, up to 3 expansion racks per system.
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Product Overview
The CJ1W-II101 is the I/O Interface Unit that terminates the I/O expansion bus on each CJ-series expansion rack. One CJ1W-II101 is required per expansion rack — it mounts immediately to the right of the expansion rack's power supply unit and converts the daisy-chained CS1W-CN@@3 cable signal from the CPU rack's CJ1W-IC101 into the local expansion rack's I/O backplane bus. Without the II101 on the expansion rack, the rack's power supply will power up (the green PWR LED will be lit) but the CPU will not be able to see any of the I/O modules mounted on that rack.
Where the CJ1W-II101 sits in the CJ1 / CJ2 expansion rack layout
Like the CJ1W-IC101, the CJ1W-II101 has a strict mounting rule: it MUST be the first module to the right of the expansion rack's power supply unit. The full expansion rack sequence is: Power Supply (CJ1W-PA202 / CJ1W-PD025) → CJ1W-II101 (this SKU, always first to the right of PSU) → remaining CJ1W basic I/O, special I/O, and CPU bus units on the expansion rack → End Cover (CJ1W-TER01). The II101 occupies a logical position but does not consume a logical I/O slot — it is transparent to the I/O allocation table.
Cable topology and rack-to-rack daisy-chain
The CJ1W-II101's front-panel 40-pin connector accepts the same CS1W-CN@@3 cable family that connects to the IC101. The cable model encodes the length: CS1W-CN313 = 0.3 m, CS1W-CN713 = 0.7 m, CS1W-CN223 = 2 m, CS1W-CN133 = 10 m. The physical topology for a 3-rack expansion system is: CPU rack (IC101) → CS1W-CN@@3 cable → expansion rack 1 (II101) → CS1W-CN@@3 cable → expansion rack 2 (II101) → CS1W-CN@@3 cable → expansion rack 3 (II101). Each II101 on racks 2 and 3 has TWO cable connections — one incoming from the previous rack (or CPU rack), and one outgoing to the next rack.
Compatibility with NJ-series Machine Controllers and CS1 migration
Like the CJ1W-IC101, the CJ1W-II101 is fully compatible with the NJ-series machine controllers (NJ101-1000, NJ301-1200, NJ501-1300/1400/1500) when CJ1W expansion racks are added to the NJ CPU. For CS1-to-CJ1/CJ2 migration: if you are replacing a CS1H or CS1G CPU with a CJ2M or CJ2H, the CS1W-II101 must be replaced with a CJ1W-II101 — the connectors and firmware differ. Conversely, if you are keeping a CS1 CPU and want to add modern CJ1W I/O, you must use the CS1W-II101 (not the CJ1W-II101) on the expansion racks.
Key Features
- I/O Interface Unit for CJ-series expansion rack
- One CJ1W-II101 required per expansion rack
- Mounted immediately to the right of the expansion rack power supply
- Connects to CJ1W-IC101 or previous II101 via CS1W-CN@@3 cable
- Standard 31 mm wide CJ1W module form factor
- 5 VDC backplane current consumption 0.02 A
- No settings required — plug-and-connect, fixed function
- Total cable length across all expansion racks must not exceed 12 m
- SKU: CJ1W-II101
- Series: CJ-series I/O Control / Interface
Best-Fit Applications
- Expansion rack 1 of a CJ2M-CPU33 system with CJ1W-ID211 inputs and CJ1W-OC211 outputs — II101 on the expansion rack side.
- Three-rack expansion system for a large packaging line with the CPU rack at the operator station and three expansion racks.
- Migration of an existing CS1W expansion rack design to a CJ2M-CPU33 — replace the CS1W-II101 with CJ1W-II101
- Long-distance expansion up to 10 m between adjacent racks using CS1W-CN133 cables — for large-machine layouts where racks are physically separated
Buying Checklist
- Pick CJ1W-II101 for CJ1 / CJ2 / NJ expansion rack I/O termination
- Pick CS1W-II101 for CS1-series expansion racks — NOT interchangeable with CJ1W-II101
- Pick CS1W-CN223 for typical 2 m rack-to-rack cable
- Pick CS1W-CN713 for 0.7 m cable
- Pick CS1W-CN313 for 0.3 m cable
- Pick CS1W-CN133 for 10 m cable
Technical Specifications
| Model | CJ1W-II101 |
|---|---|
| Series | CJ-series I/O Control / Interface |
| Type | I/O Interface Unit for expansion rack |
| Mounting Position | Immediately to the right of the expansion rack PSU (mandatory) |
| Number per System | 1 per expansion rack (max 3 per CJ CPU) |
| Connected Unit | CJ1W-IC101 (rack 1) or previous CJ1W-II101 (racks 2 and 3) |
| Maximum Expansion Racks | 3 (CJ1M / CJ2M / CJ2H / NJ series); 2 (CJ1G-CPU42H/43H legacy) |
| Total Cable Length Limit | 12 m maximum across all racks |
| Connector Type | 40-pin high-density connector on front face |
| Current Consumption (5 V) | 0.02 A |
| Current Consumption (24 V) | 0 A (no 24 V consumption) |
| Operating Temperature | 0 to +55 °C |
| Storage Temperature | -20 to +75 °C |
| Certifications | UL (UC1), CSA (N), Lloyd's (L), CE |
Resources & Downloads
FAQ for CJ1W-II101
Does every CJ expansion rack need a CJ1W-II101?
Yes — exactly one CJ1W-II101 is required per expansion rack. The II101 is the bus-termination module that converts the daisy-chained CS1W-CN@@3 cable signal from the CPU rack into the local I/O backplane bus.
Can I use a CS1W-II101 instead of a CJ1W-II101?
No — the CS1W-II101 and CJ1W-II101 are physically and electrically different. The CS1W-II101 has a different front-panel connector pinout and firmware revision than the CJ1W-II101. Plugging a CS1W-II101 into a CJ1 / CJ2 / NJ CPU system will not work (the CPU will not recognise it, or it may damage the bus). Plugging a CJ1W-II101 into a CS1 CPU system will also not work.
What's the maximum number of expansion racks per CJ CPU?
3 expansion racks maximum for the CJ1M, CJ2M, CJ2H, and NJ-series CPUs (with the NJ101 / NJ301 / NJ501 family). So you need 1, 2, or 3 CJ1W-II101 modules depending on how many expansion racks you use. The older CJ1G-CPU42H and CJ1G-CPU43H support only 2 expansion racks (so up to 2 II101 modules). The CS1G-CPU43H / CS1G-CPU42H / CS1G-CPU44H / CS1G-CPU45H also support 3 expansion racks (using CS1W-II101).
What happens if I mount something between the PSU and the II101?
The I/O expansion bus will not propagate, and the CPU will not see any I/O modules on that expansion rack. The CJ1W-II101 has the same strict mounting rule as the CJ1W-IC101: it MUST be the first module to the right of the expansion rack's power supply. If you have a CJ1W-ID211 input module or any other CJ1W module between the PSU and the II101, the bus signal will be blocked and the CPU will report an I/O verification error.
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