Imperx Cheetah C2020 User Manual page 50

Cheetah Pregius Camera with Camera Link – User Manual
You can update each camera control register independently. The serial protocol defines
all registers as 16-bit address (hex format) and 32-bit data (hex format). Camera registers
using fewer than 32-bits in width must be padded with 0s on writes; unused bits are
ignored on reads. Register data is always packed low within 32-bit data words for registers
defined less than 32-bits.
Each command experiences delay due to command execution and data transmission over
the serial port. This latency varies from command to command because of resource
location and command response length.
5.1.1.1 Write Operation
To write to any given camera register, send a sequence of 7 bytes to the camera. If there
is no error, the camera returns a one byte acknowledge for the write command <Ack>.
Write to camera (7 Bytes): <Write_Cmd> <Address> <Data>
Write Acknowledge (1 Byte): <Ack>
If there is an error, the camera returns two bytes not-acknowledge for the write
command – the first byte is <Nac> <Err>, the second is the error code as shown in the
following diagrams:
Write Not-acknowledge (2 Bytes): <Nak> <Error Code>
July 6, 2018
Figure 36: RS-232 serial protocol format
1st byte: 0x57 (Write Command)
2nd byte: <Register Address_High> MSB
3rd byte: <Register Address_Low> LSB
4th byte: <Register Data Byte 4> MSB
5th byte: <Register Data Byte 3> ...
6th byte: <Register Data Byte 2> ...
7th byte: <Register Data Byte 1> LSB
1st byte: 0x06 (Acknowledge)
Figure 37: Normal write cycle
1st byte:0x15 (Not-acknowledge)
2nd byte: <XX> (Nck Error Code. See Error Code Description section)
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