UNIVERSAL DIGITAL AND DATA INTERFACE
B-6
Revised May 1998
Part No. 001-9750-006
OUTPUTS
RSSI Out
21
Direct analog RSSI (Received Signal Strength Indicator) output. The DC voltage of this output
decreases from 8 - 0 volts as signal strength increases. Output impedance is greater than 100k
ohms.
AUX1
14
Active high output which is controlled by the AUX 1 option switch or menu parameter (see Sec-
tion 3.5.4). This output can be used to control an external accessory. The output levels are 0 and 8
volts DC ±10%. Maximum source current is 50 mA. Therefore, a driver circuit of some type may
be required. This output is shared with the option wire-out 8.
PTT
5
Active low output which provides the PTT signal to an external device. This output is shared with
the option wire-out 9. Programmable options are as follows. (With the Viking HT, this signal is
active high.)
Tx Sense (default) -
Indicates that the transmitter is currently activated.
Standard -
Indicates that the microphone PTT switch is pressed (the transmitter may or may not
be activated, depending on the current mode).
Busy Out
6
This output which provides channel/system information to an external device. Programmable
options are as follows:
Access Denied (default) -
When accessing the system/channel, this output indicates a busy or
out-of-range condition. This output is active low.
RSSI -
Output from the RSSI (Receive Signal Strength Indicator) circuit. This is a logic output
that reacts faster than noise squelch. Therefore, it is also subject to more falsing. Typical noise
squelch response at -116 dB is 50 ms with 6 dB of hysteresis, and typical RSSI response at this
level is 5 ms with 4 dB hysteresis. This output is active high.
Output A
15
Multi-purpose output programmable for the following functions. This is a CMOS output that can
source up to 20 mA as described in Section 6. It is shared with option wire-out 7.
NOTE: When
the encryption option is installed, this option is dedicated to the Clear Code function and the
other options are not available.
Clear Code (default) -
Active high output that indicates that the transmit audio signal is to be
encrypted.
Clear-to-Send -
Active low output that indicates that a trunking channel has been accessed and
all overhead activities completed. This function is also programmable for Output B.
Monitor Hanger -
Active low output that indicates that the microphone is on-hook (a high indi-
cates that it is off-hook). This function is also programmable for Output B.
Tx Audio Enable -
Active high output that indicates that the internal transmit audio signal is
muted. This function is also programmable for Output B.
Auxiliary 2 -
Same as the following Output B function.
Output B
16
Multi-purpose output programmable for the following functions. This is a CMOS output that can
source up to 20 mA as described in Section 6.
Auxiliary 2 (default) -
Active high output which is controlled by the AUX2 option switch or
menu parameter (see Section 3.5.4). This output can be used to control an external accessory. The
preceding Output A parameter can also be programmed for this function.
Rx Data Group -
Active low output that indicates that a call is being received on a group pro-
grammed for data signaling (see Section 3.6.11).
Clear-to-Send -
Same as preceding Output A function.
Monitor Hanger -
Same as preceding Output A function.
Tx Audio Enable -
Same as preceding Output A function.
Table B-6 Control Signal Description (Continued)
Function
Pin
Description
Summary of Contents for Summit DM 975x
Page 105: ...MULTI NET SYSTEM OVERVIEW 5 10 Revised February 1997 Part No 001 9750 005 ...
Page 108: ...CIRCUIT DESCRIPTION 6 3 August 1993 Part No 001 9750 001 Figure 6 1 Transceiver Block Diagram ...
Page 123: ...CIRCUIT DESCRIPTION 6 18 August 1993 Part No 001 9750 001 ...
Page 131: ...SERVICING 7 8 Revised January 1995 Part No 001 9750 003 ...
Page 156: ...9 19 Revised December 2000 Part No 001 9750 007 TRANSCEIVER EXPLODED VIEW PART 1 ...
Page 168: ...Revised January 1995 Part No 001 9750 003 10 11 INTERCONNECT SCHEMATIC ...
Page 169: ...Revised January 1995 Part No 001 9750 003 10 12 DISPLAY BOARD SCHEMATIC ...
Page 171: ...Revised January 1995 Part No 001 9750 003 10 14 RF BOARD SCHEMATIC REVISED 800 MHZ ...
Page 172: ...Revised January 1995 Part No 001 9750 003 10 15 RF BOARD BOARD LAYOUT ALL 800 900 MHZ ...
Page 173: ...Revised January 1995 Part No 001 9750 003 10 16 RF BOARD BOARD SCHEMATIC 900 MHZ ...
Page 174: ...Revised January 1995 Part No 001 9750 003 10 17 RF BOARD BOARD SCHEMATIC UNREVISED 800 MHZ ...
Page 178: ...Revised January 1995 Part No 001 9750 003 10 21 PA BOARD SCHEMATIC 900 MHZ 30W ...
Page 179: ...Revised January 1995 Part No 001 9750 003 10 22 PA BOARD SCHEMATIC 900 MHZ 15W ...
Page 181: ...Revised January 1995 Part No 001 9750 003 10 24 PA BOARD SCHEMATIC UNREVISED 800 MHZ 35W ...
Page 182: ...Revised January 1995 Part No 001 9750 003 10 25 PA BOARD SCHEMATIC UNREVISED 800 MHZ 15W ...
Page 183: ...Revised January 1995 Part No 001 9750 003 10 26 AUDIO LOGIC BOARD SCHEMATIC PART 1 OF 2 ...
Page 184: ...Revised January 1995 Part No 001 9750 003 10 27 AUDIO LOGIC BOARD SCHEMATIC PART 2 OF 2 ...
Page 185: ...Revised January 1995 Part No 001 9750 003 10 28 AUDIO LOGIC BOARD LAYOUT TOP VIEW ...
Page 186: ...Revised January 1995 Part No 001 9750 003 10 29 AUDIO LOGIC BOARD LAYOUT BOTTOM VIEW ...
Page 188: ...Revised January 1995 Part No 001 9750 003 10 31 REMOTE TRANSCEIVER INTERCONNECT SCHEMATIC ...
Page 189: ...Revised January 1995 Part No 001 9750 003 10 32 REMOTE CONTROL UNIT INTERFACE BOARD SCHEMATIC ...
Page 216: ...Part Number 001 9750 007 12 00 hph Printed in U S A ...
