C
HEETAH
864XR
V
IDEO
M
ATRIX
S
WITCHER
Publication 81-9059-0595-0, Rev. C
October 2010
Proprietary Information of
PESA
3-16
Table 3-5 - Com 3/PRC Pin Assignments
Pin
Signal
In/Out
1
CTS+
Input (not used)
2
Bi-directional
3
CTLR-
Output
4
RTS-
Output (not used)
5
Ground
---
6
CTS-
Input (not used)
7
MATRIX- Bi-directional
8
CTLR+
Output
9
RTS+
Output (not used)
COM 4 is an RS-422 CPU Link similar to the RS-232 CPU Link, except the interconnect cable may
be up to and including 4,000 feet in length. When using this communication protocol an RS-422
interface card must be installed in the computer chassis used for system control. COM 4 may be used
with either of the protocols listed in the previous Table 3-4. Refer to Table 3-6 for pin assignments)
Table 3-6 – COM 4 Pin Assignments
Pin Signal
In/Out
1
CTS+
Input
2
RX+
Input
3
TX-
Output
4
RTS-
Output
5
Ground
---
6
CTS-
Input
7
RX-
Input
8
TX+
Output
9
RTS+
Output
3.9.3
S
YSTEM
C
ONTROL
A
LARM
C
ONNECTOR
The three-pin System Control Alarm Connector, illustrated in Figure 3-12, provides an interface for
an external, customer-supplied system control alarm notification device. An alarm condition is
initiated by the system controller and is declared when the controller is in reset and when the standby
controller is gathering configuration information from the primary controller. During an alarm
condition, an optically isolated, electronically closed circuit exists between contacts 2 and 1 as shown
in Figure 3-13. This circuit acts as a switch to trigger an optional external alarm in the event of a
controller fault or failure. The controller alarm circuit supplies an electronic contact closure, but does
not provide a voltage to the external alarm. The customer-supplied circuitry must not exceed
12VDC @ 10mA.
