By office environment we mean:
- The equipment is indoors in a temperature range between 10 and 40 C
- Employee clockings are usually varied and not only IN/OUT
- Clockings don’t only occur at short peak times, but are more distributed
Time and attendance recording in an office environment can be accomplished in several ways:
SL-87 terminals
If there is a LAN switch near the locations where the terminals should be placed and the number of terminals is four or less, the SL-87 terminal is a good choice.
The SL-87 is available with an iButton or an RF tag reader. They can be connected directly to a LAN and the power supply is via the LAN cable. Two power supply/switch/battery-backup units are available> the SL-876 for two SL-87 terminals and the SL-877 for four SL-87s.
SL-87 connection
It is possible to use SL-87 terminals without the SL-876/877 power supply units by connecting them directly to a LAN switch and using 12-40VDC power supplies (although no battery backup would be available). The power would be connected to a screw terminal on the SL-87 PCB instead of via the UTP/STP cable.
SL-88 controller and various readers/terminals
The SL-88 controller has two AUX channels and no relay outputs. It is well suited to systems not requiring access control, driving jingle networks for announcing shifts, coffee breaks etc. and signal outputs for random events: spot searches, alcohol and drug tests etc.
(The AUX interface is a way to connect devices to a controller in a daisy-chain. A single (UTP/STP) cable is used to carry both signals and power. AUX devices don’t buffer data and have no clock ICs, but send the clockings straight to the controller.)
On the other hand, two AUX channels enable a wide network of readers/terminals spanning up to 120m in range.
Considering that you can connect up to 4 terminals or 16 readers (e.g TK-2, SL-8471, with the SL-862 TK/AUX adapter) to an AUX channel, the SL-88 is the most economical choice for situations where a large number or readers is needed at a single site.
SL-88 connection