MD-81
RS-232 to Wiegand Output Convertor
Installation Manual
1
1. Introduction
The MD-81 is designed to be used with the AY-U900 and AY-U910
UHF readers. It converts the UHF reader data from RS-232 to a stream
of ID data in either Wiegand 26-Bit or a Wiegand 34-Bit format. The
Wiegand format is determined by the UHF reader.
The MD-81 allows the AY-U900/U910 to read the ID of up to 70 cards
via RS-232 and then send each card’s ID output one by one every 2.5
seconds to the access controller in Wiegand data format.
1.1 Box Content
1 MD-81 unit
1 RS-232 cable
1 RS-232 transfer connector
Figure 1: MD-81
2. Technical Specifications
2.1 Electrical Characteristics
Operating Voltage 12 to 15 VDC
Operation Current 23 to 30 mA
2.2 Environmental Characteristics
Operating Environment Indoor use only
Operating Temperature Range 0°C to 63°C (32°F to 145°F)
Operating Humidity Range 0 to 95% (non-condensing)
2.3 Physical Characteristics
Dimensions 80 x 66 x 28 mm (3.2 x 2.6 x 1.1 in.)
Weight 75 g (2.6 oz)
3. Connecting the MD-81
Refer to Figure 2 below when connecting the MD-81 convertor.
When connecting the MD-81 with the UHF reader, the UHF
reader must be in Command mode, which is set using the UHF
ReaderApplication (see the AY-U900/U910 installation and
software manuals.
1. Connect the RS-232 cable (included) between the AY-U900/U910
reader and the MD-81.
2. Connect the MD-81 terminals to the access controller Wiegand
reader port (4-wires).
3. Connect power to the UHF reader
4. Connect power to the MD-81, either from the controller or from
an external power supply.
If the MD-81 is connected to a controller using the the 12 V
terminal block, no external 12 VDC power supply is needed.
If the MD-81
is connected to an external 12 VDC power supply, the 12
V terminal block must be disconnected.
5. Power on the UHF reader and then power on the MD-81.
Figure 2: MD-81 Wiring
