Telex IP-223 - Manual (Page 27)

29
Tone/Console Operation
Digital I/O
In addition to the two standard relay closures, seven (7) lines of digital I/O are also included. These lines are open-collector
transistor outputs. They can be programmed on a per line basis to generate any of 128 combinations. They pull down to ground
and can be jumper selected to pull up to either +5V or the power supply voltage (minimum +12V).
Jumpers J8 (line 1) and J30 (line 2) are used to select the pull up voltage. Jumper position A pulls up to +5V and jumper
position B pulls to the power supply value.
NOTE: Some radios provide a pull-up voltage. When this occurs, place the jumper into the null position. Information on
programming the digital I/O lines is provided in the “Setup Information” chapter of this manual starting on
page 33.
CTCSS (Continuous Tone Coded Squelch System) Connection
The IP-223 connection can be used for a recorder output or as a CTCSS output:
Recorder output - The analog audio is generated at the connection.
CTCSS output - Each function tone can be assigned a CTCSS number which corresponds to a CTCSS frequency. See
“CTCSS Tone Frequency Table” on page 131.
Tone/Console Operation
Tone and Console operation require jumpers set to specific locations. The following section discusses the jumper settings. See
“Jumper Locations” on page 125.
2-/4-Wire Jumper Settings
The RX termination J14 (line 1) and J24 (line 2) should be placed in jumper position A on 4-wire systems for a single unit at
the end of a line. If multiple units are connected in parallel, only one (1) unit should have the RX termination jumper in the A
position. The RX termination jumper should be in the null position on the rest of the units.
For 2-wire operation:
• PCB 750743 or PCB 750630 revision C and higher - Set J14 or J24 to the NULL position.
TX Side Settings
PCB 750743 or PCB 750630 revision C and higher
Two (2) jumpers on the transmit pair allow a degree of control over the output impedance. The jumper positions for each line,
depending on how many consoles are placed in parallel, are shown below.
NOTE: PCB 750630 revision A does not have these jumpers.
2-Wire / 4-Wire Selection: Line 1 Line 2
2-Wire A position J33 and J34 J5 and J6
4-Wire B position J33 and J34 J5 and J6