E F Johnson Company 2422001-1 Benutzerhandbuch
CIRCUIT DESCRIPTION
6-31
August 2000
Part No. 001-2001-200
bus indicates which repeaters are in use and also
which mobiles are using the system. This information
is used by the repeater to encode data messages to the
mobiles that are monitoring that channel. These mes-
sages also include information on which repeater is
free and current system priority.
which mobiles are using the system. This information
is used by the repeater to encode data messages to the
mobiles that are monitoring that channel. These mes-
sages also include information on which repeater is
free and current system priority.
Pins 25-26
UNUSED
Pins 27/59
-5V IN
This is the -5V input to the MPC from the power
supply via the Controller backplane.
Pins 28-29
+5V IN
Pins 60-61
This is the +5V input to the MPC from the power
supply via the Controller backplane.
Pins 30/62
+15V IN
This is the +15V input to the MPC from the
power supply via the Controller backplane.
Pins 31-32
GROUND
Pins 63-64
This is the ground connection to the MPC from
the power supply via the Controller backplane.
Pin 47
READ
Read is used with the MREQ line to read data
from the main processor and external memory.
Pin 48
WRITE
Write is used with the MREQ line to write data to
the main processor and external memory.
Pins 49-55
UNUSED
Pins 57-58
6.9.6 J1 COMPUTER CONNECTOR
J1 is the MPC connection to the computer or
modem.
Pin 1
Ground
Pin 2
Computer Tx
Pin 3
Computer Rx
Pin 4
Modem DCD
6.9.7 J2 MEMORY SELECT
J2 is jumpered to select either the Flash memory
or the EPROM memory. Flash memory is ultra-fast
data storage. The normal setting is pin 1 to pin 2.
data storage. The normal setting is pin 1 to pin 2.
Pin 1
+12V
Pin 2
U25, pin 1 Vpp
Pin 3
+5V
6.9.8 J3 BAUD RATE
J3 is jumpered to select the baud rate from the
computer to the MPC, these two baud rates must be
the same (see Figure 6-17). The baud rate of the com-
puter can be found from the command line by request-
ing /b, /h or /? (see Section 3.1.5). To change jumper
J13: Power off the station. Move P3 to the proper
rate. Power on the station.
the same (see Figure 6-17). The baud rate of the com-
puter can be found from the command line by request-
ing /b, /h or /? (see Section 3.1.5). To change jumper
J13: Power off the station. Move P3 to the proper
rate. Power on the station.
6.9.9 S2/S3 HSDB SETTINGS
These switches configure; the HSDB for RS-485
or single-ended 5V operation, indicate if the Summit
repeaters are connected to existing repeaters or only
Summit repeaters, and if the repeater is an end
repeater termination. Refer to Sections 2.9 and 7.4.8.
repeaters are connected to existing repeaters or only
Summit repeaters, and if the repeater is an end
repeater termination. Refer to Sections 2.9 and 7.4.8.
6.9.10 J4 EPROM MEMORY LOADING
This jumper selects EPROM memory loading for
LTR systems. The LTR setting is pin 3 to
pin 4.
pin 4.
6.9.11 J5 HSDB SPEED
J5 is jumpered to select the data bus speed. J5,
pins 2/3 select the LTR 12 MHz crystal.
6.9.12 J6 WATCHDOG
This jumper enables or disables the watchdog
timer for reset. Normal operating mode is P6 jumper-
ing J6, pins 2/3. This jumper should not be moved or
removed.
ing J6, pins 2/3. This jumper should not be moved or
removed.