M10510B;26/58
- 26 -
(7-4) How to set Gain
“G” command is used for gain setting.
Transmission from host: STX : “G” : MGC set value : AGC set value : (VRT set value) : VRB set value : OFFSET set value : ETX
Return by camera:
STX : ACK : ETX (transaction completion) or STX : NAK : ETX (transaction rejection)
●
MGC gain setting … Setting the fixed gain.
[Example] To set the MGC gain to “123”(=H’7B)
Transmit as follows
Transmission from host: STX: “G”: “7B” : “….” ETX
(Note) “….” (four periods)
Right figure shows the example of transmitting the command using
FCTool. The MGC set value is set to “7B”.
●
AGC gain setting … Setting the AGC gain (reference value).
[Example] To set the AGC gain to “82”(=H’52)
Transmit as follows
Transmission from host: STX: “G” : “ .” : “52” : “ … ” ETX
●
Gain setting in AEC…. In AEC (Auto Exposure Control), AGC gain set value is applied as the reference value and MGC set
value as the fixed preamplifier gain value.
When AEC function is ON, the value displayed at the left side of GAIN
column on OSD menu is MGC set value, and the value displayed at the right
side is AGC set value.
(
→
MGC set value=75, AGC set value=70 in the right example)
In the AEC function, the shutter exposure time is automatically controlled
with reference to AGC set value( comparative level).
The average of image output level is increased or decreased in proportion to
AGC set value.
Increase the AGC set value when it is needed to increase the output image luminance.
Preamplifier gain of A/D converter is defined in terms of MGC gain value.
MGC gain value can be set independently of AGC set value.
If MGC set value is increased, the sensitivity is improved but the S/N ratio degrades.
[Example] To set AGC set value (reference value) to “75” (=H’4B) and MGC set value(preamplifier gain) to “100” (=H’64) .
Transmit as follows
Transmission from host: STX: “G”: “64” : “4B” : “…” ETX
[Explanation] The replacement of set value by “ . “
It can use “ . “ as replacement of the parameter value which should not be changed, if it is needed to change only the specific
parameters by the communication command accompanying plural parameters such as “G” command.
For example, in the case of AGC gain setting four “ . “ are used as replacement of each of “MGC”,”VRB”,”VRT” and “OFFSET”.
Image output
to GiGE I/F
Ｃ Ｃ Ｄ
Preamplifier
ＧＡＩＮ
S/H
Ａ ／ Ｄ
COMP
Log ical comparison
AGC set value
MGC set value
Shutter exposure time control
Bl ock diagra m of AEC control
*MENU
１
MENU
:
ON
GAIN
:
75
/
70 AEC
OFFSET:
140
S.TIME:A 484 h
(
14.31)ms
S.FORM: NORMAL
AEC ON
/
Menu1 display