Ch 1 Installation
1-4
end of the chain. Due to the male/female polarization, the network cannot be
installed incorrectly with instruNet Male-Female cables.
3. Each Controller includes Timer I/O Channels
Each Controller (except iNet-230 PC-Card) provides 10 Timer I/O channels.
Each channel can be programmed as a digital input, digital output (0V/4V TTL
compatible), clock output, or period measurement input.
4. Each Controller includes one Terminator
One instruNet Terminator must be installed at the end of each network chain.
This terminator mates with the output connector of the last device. instruNet
Controllers include an instruNet Terminator, therefore they do not need to be
purchased separately. Caution: Do not use a SCSI Terminator in place of an
instruNet Terminator -- they are different.
5. Each Network Device includes one cable
Each instruNet Network Device is shipped with one 10foot DB-25 Cable
Male/Female cable for purposes of configuring your network.
6. You can purchasing your own cables
If you want a specific cable length, you can purchase your own DB-25 male to
DB-25 female, shielded, wired point-to-point (i.e. pin X to pin X) cables. We
recommend 24 gauge wire for > 4 meters; however 28 gauge is fine with ≤4m.
Twisted pairs are recommend for >4 meters with the following wires twisted: 1
& 14, 2 & 15, 3 & 16, 4 & 17, 5 & 18, 6 & 19, 7 & 20, 8 & 21, 9 & 22, 10 &
23, 11 & 24, 12 & 25 (these are physically next to each other in the connector).
Also, it is recommended that the drain wire (which is attached to the shield) be
connected to the housing and pin #1 (GND) on both connectors. For more
information on cables, please refer to Application Note #22, Third Party
instruNet Cable Suppliers; and Application Note #39, Use Low Capacitance
Cable to Maximize your instruNet Network Speed.
A supplier of high quality twisted pair, low capacitance, double-shielded cable
without connectors is Belden, Inc. The Belden Cable Part #8112 Low
Capacitance RS-485/RS-232 cable is available in 100ft, 500ft, and 1000ft
lengths with 12.5 Pairs and a copper braided shield. This cable features 24
gage wire, 41pF/meter between pairs, 72pF/meter between a wire and the
shield, and 78ohms/killometer wire resistance
7. Minimum Base System
One Controller and one Network Device is all you need to purchase to digitize
waveforms, save them to disk, and view them.
8. Maximum Sample Rate
As the physical length of the network increases, the maximum aggregate data
acquisition sample rate decreases from 166Ks/sec maximum with a short
network (e.g. 5 meters) to 4.15Ks/second aggregate with a long network (e.g.
300 meters).