What is the Device Interface Definition of FOG North Seeker

1.Application products

ER-FNS-03 Low Cost 3 Axis FOG North Seeker

2.1 Data Interface

The SX1 connector leads to a J30J-21ZK connector, which is connected to a standard four-wire RS422. Users only need to connect the above serial port to the acquisition computer for measurement. Note that the baud rate is 614.4 kbps, which requires a matching acquisition device for data acquisition.

2. 2 Wiring definition

Table 5 Wiring definition：J30J-21ZK

2.3  Data Receiving Protocol From North seeker to Computer

ER-FNS-03 series north finder adopts RS422 serial port output. The baud rate is 19200bps. Each frame has a total of 60 bytes. Each byte contains 1 start bit (0), 8 data bits, 1 stop bit (1), each word. The lower part is transmitted first in the section, and the low byte is transmitted first for each frame of data, and there is no verification at this moment. The specific data format is shown in the following table:

Table 6 data frame format

2.4  Data Transmit Protocol From Computer to North seeker

2.4.1 Total number of bytes delivered at a time: 21 bytes, baud rate 19200bps, no parity check. Each byte contains the start bit (0), data bit (8), and stop bit (1).

Start the work

2.4.2  Send warp and weft height

Determine the definition of the data sent according to byte 4:

1. If control_FLAG ==0xCC: Restarts
2. If control_FLAG ==0xAA: Indicates the altitude of the latitude and longitude to be sent

Send order: 5-8 bytes: latitude (* 1E6, unit °)

9-12 bytes: Longitude (* 1E6, in °)

13-16 bytes: Height (*1, in m)

For example, C code that sends Latitude and longitude instructions (the rest of the byte configuration is arbitrary), Latitude is “Latitude *1e6”, longitude is similar, height ratio is 1.

bytSend[0] = 0xeb;

bytSend[1] = 0x80;

bytSend[2] = 0x00;

bytSend[3] = 0xaa;

bytSend[4] = (Latitude>>24) & 0xff;

bytSend[5] = (Latitude>>16) & 0xff;

bytSend[6] = (Latitude>>8) & 0xff;

bytSend[7] = (Latitude) & 0xff;

bytSend[8] = (Longitude>>24) & 0xff;

bytSend[9] = (Longitude>>16) & 0xff;

bytSend[10] = (Longitude>>8) & 0xff;

bytSend[11] = (Longitude) & 0xff;

bytSend[12] = (Height>>24) & 0xff;

bytSend[13] = (Height>>16) & 0xff;

bytSend[14] = (Height>>8) & 0xff;

bytSend[15] = (Height) & 0xff;

bytSend[16] = 0xaa;

bytSend[17] = 0xbb;

bytSend[18] = 0xcc;

bytSend[19] = 0xdd;

bytSend[20] = b[4]^b[5]^…b[19];