Installation manual

Regency

Model 4734 Access Control Expander Installation Manual (P/N 150807, Rev. A) Revised 5/98

Section 2: Installation

NOTE 1. Because the 4724 and 4734 have different options, you cannot convert a 4724 into a 4734 by

replacing a chip.

2. The 4734 is for use with the 4720 Revision M circuit boards; the 4734-2 is for use with the

4720 Revision N or later circuit boards. When referring to both the 4734 and the 4734-2, these

instructions use the convention “4734/4734-2.” (The 4734/4734-2 cannot be used with Revi-

sion A-L 4720 boards.)

Figure 1 on the next page shows the placement of the 4734/4734-2 board in relation to the

4720.

The Model 4734N is a 4720 and a 4734-2 (shipped together), which has been partially installed

at the factory.

Maximum current draw for the 4734/4734-2 is 50 mA.

2.1 4734 Installation

1. Very important. Remove power from the 4720 by disconnecting the AC power and bat-

tery.

2. (Skip this step if you are installing a 4734N.) Carefully remove the 4720 control micro-

processor chip from its socket by inserting a flat-blade screwdriver under each end of the

microprocessor and prying it out slowly.

If you are installing a 4734-2 board, which has a socket for this chip, press the chip into

the socket. Observe proper polarity (it is the opposite of the other large ICs).

If you are installing 4734-2 board which does not have a socket for this chip, the chip is no

longer needed because the 4734-2 has its own control chip. If you want to, you can save

the chip for later use (for example, in case you ever need to downgrade a 4734-2 back into

a 4720).

3. (Skip this step if you are installing a 4734N.) Insert the socket adapter into the 4720 con-

trol microprocessor socket. Pin 1 (marked on the adapter) goes in the upper left hand cor-

ner of the socket. Make sure all pins are aligned. Press adapter in, making sure the adapter

is fully seated (this requires a fair amount of pressure).

4. Remove the lower left hand mounting screw from the 4720 panel. The screw will no

longer be used. (If an earth ground wire was attached at this screw move the wire to

another mounting screw.)

5. Place the 4734/4734-2 circuit board over the pins on the socket adapter. The plastic

mounting bar should extend down over the mounting hole. Carefully press the 4734/4734-

2 onto the socket adapter. The 4734/4734-2 will rest level on the 4720 with the mounting

hole aligned with the hole in the mounting bar.

6. Fasten the 4734/4734-2 to the 4720 by placing the long 6-32 Phillips screw (provided)

through the mounting bar into the mounting hole and tightening the screw.

7. Reconnect power to the 4720 and turn on. The normal power-up display is “Default in

250s. Press CLR.”

NOTE The 4791 EEPROM chip on the 4720 is not used by the 4734/4734-2 and may be removed if

desired. The 4734/4734-2 has its own EEPROM.