Remote Technologies RPC-320 RAM Memory, Changing Memory, Battery Backup, Checking the battery

RAM MEMORY

INTRODUCTION

32K, 128K, or 512K of RAM may be battery backed on the RPC-320. RA M size can be changed at any time. RAM is in socket U5.

RAM is backed up when a DS1216DM is installed. Battery life depends upon RAM size, its power consumption, ambient temperature, and amount of time the board is operating. Gener ally, a battery life of about 3 to 5 yea rs is e xp ec ted . Op er ati ng the bo ar d a t 50 °C reduces battery life by 1/2.

The DS1216DM is also a real time clock . Thus, DATE and TIM E function s and com mands a re availa ble when it is installed. See Chapter 7 for more inform ation.

This chapter discusses changing RAM, saving and retrieving variables, r unning assembly language program s, and battery condition. F igure 5-1 shows the location of U3 and jumper W1.

Increasing RAM size does not necessarily increase the program size RPBASIC-52 can handle. Maximum program and variable size is 60K. Additional RAM does increase the amount of space available for PEEK and POKE storage.

Figure 5-1 RAM and W1 ju mper location

CHANGING MEMORY

Different types of memory can be installed at any time. RPC-320 models come with either 32K or 128K of RAM installed. Maximum is 512K.

To change a mem ory chip, you need to rem ove the original chip, install the new one, and set jumper W 1.

SECTION 5

To install a new memory chip:

1.Turn off power to the RPC-320.

2.Remove the mem ory chip from U 5.

3.Orient the chip so pin 1 is towards the inside.

If installing a 32K RAM , place the chip at the bottom of the socket (m emor y chip pin 1 goe s into socket pin 3). The top two socket pins in each row are empty.

If installing a 128K or 512K, install the chip into the socket.

4.Check and change , as n ecessar y, jum per W 1 to conform to the new mem ory.

RAM size	Jumper W1
32K	[1-2]
128K	[1-2]
512K	[2-3]

BATTERY BACKUP

An optional battery backup module may be installed. Principal is the same as installing a RAM chip.

WARNING:

An additional modification must be performed to the DS1216DM module when a 512K RAM is installed. Contact Rem ote Processing fo r details.

To install a module:

1.Remove the RAM IC in U5.

2.Install the DS1216DM in U5.

3.Re-install the RAM chip into the top of the module.

Checking the battery

Battery voltage is approximately 3.0 volts, measured between pin 16 (ground) and 30 (128K RAM ), 14 and 28 (32K RA M), or 16 and 32 (512K R AM ) on the IC itself (not the circuit side of the board). Be sure to pow er up the RPC -320 once to a ctivate the batter y backup cir cuit in the module.

Page 5-1 RPC -320