6
Rev A
GPS Identification Bits, JP5 and JP6
This module was designed to be used with multiple data sources through the use of both
mezzanine cards to replace the Novatel SSII as well as multiple serial peripherals accessible
from the EXT GPS/Data port, J7. To allow user software identification of the type of GPS/
Module connected/installed on the MBS-GPS-SS2-5HZ JP5 and JP6 are available for use as
identification bits. ID bits are read by polling the DCD, DSR and CTS bits of the Differential Port.
By polling these register bits the user can identify the jumper settings and thus verify user
assigned information to these settings. If desired these could be also unused or used as user
digital inputs. Two sets of jumpers define this. These are routed dependant upon the selection of
either the INT or EXT GPS. Thus unique ID bits are available when ports are switched. Jumper
on represents a Logical 0 and jumper on represents a logical 1.
Internal or External Serial IO, JP8 and JP8A:
Note: All jumpers have positions 1-2 towards connector J7. Please refer to Figure 1.
JP7 Reset source.
In Position 1-2 reset is driven by the state of the Diff Port DTR Bit (DTR1). In Position 2-3 it is
driven by the reset switch, SW1. For default minimal SW requirements use SW1 as the source.
DTR1 requires software intervention to insure the reset line is held high. This has a advantage of
allowing the host CPU to reset the GPS if required.
JP8 Controls the serial data source.
In position 1-2 the data, PPS signal and Reset lines are routed based upon the level of the DTR
line of the Data Port. Thus if the data port is COM1 (0x3F8) then setting the DTR bit of COM1 to
1 will select the EXT Serial Port and setting the DTR bit to 0 will select the INT Novatel SSII.
In position 2-3 the data, PPS signal and Reset lines are routed based upon Jumper JP8A, not the
DTR bit of the Data Port. JP8A 2-3 selects the Novatel SSII and JP8A 1-2 selects the EXT Serial
Port.
Internal or Auxiliary 1 Pulse Per Second (1PPS) Selection, JP9 and JP9A:
JP9 Controls the 1PPS source.
In position 1-2 the 1PPS signal is routed based upon the level of the RTS line of the Data Port.
Thus if the data port is COM1 (0x3F8) then setting the RTS bit of COM1 to 1 will select the AUX
PPS input and setting the DTR bit to 0 will select the INT Novatel SSII.
In position 2-3 the data, PPS signal and Reset lines are routed based upon Jumper JP9A, not the
RTS bit of the Data Port. JP9A 2-3 selects the Novatel SSII for the 1PPS source and JP9A 1-2
selects the AUX for the 1PPS source.
Internal or External Serial IO, JP10 and JP10A:
JP9 Controls the inversion of the 1 PPS signal.
In position 1-2 the 1PPS signal is inversion is based upon the level of the RTS line of the
Differential Correction Port, or Port 2. Thus if the Diff Port is COM2 (0x2F8) then setting the RTS
bit of COM2 to 1 will invert the PPS signal regardless of the source (GPS INT/EXT or AUX) and
setting the RTS bit to 0 will un-invert the 1 PPS.