3.3 Mode and passband data format

The mode is set with command $01 or $06. The mode is defined by the first data byte following the command and can by followed by a filter width setting (see below).

CI-V frame to set mode (USB in this example, without filter value)
$FE $FE to fm $06 $01 $FD

In commands $01 and $06 (and some extended commands) where the mode is set or read, the following values are used:

Mode Data Comment
LSB $00  
USB $01  
AM $02  
CW $03  
RTTY (FSK) $04 FM on IC-910
FM $05  
Wide FM $06 IC-706xxx, IC-R8500, IC-R20
CW-R $07 CW reverse sideband
RTTY-R $08 RTTY reverse sideband
S-AM $11 Synchronous AM detection, IC-R75
PSK $12 PSK31, IC-7800 only
PSK-R $12 PSK31, IC-7800 only, reverse sideband
SSB $0500 IC-R7000 only, USB/LSB is selected via front switch

Passband data (filter width)

Mode and passband data are always transmitted together in the same command, although the passband data can be omitted. So the mode can be set without sending additional passband data, but to send passband information, the mode has to be sent always together with passband data.

CI-V frame to set mode and filter width
$FE $FE to fm $06 $01 $02 $FD

The passband data (IF bandwidth) is:

Filter setting Value
Wide $01
Medium/Normal $02
Narrow $03

Due to historical reasons the filter settings are somewhat confusing. The original CI-V protocol initially had only two settings for filter width: normal and narrow. When newer rigs came out, supporting three settings (wide, normal, narrow) the codes for the filter width had to be extended.

This leads to some confusion about which value sets which filter, further aggravated by erroneous documentation (e.g. IC-R75). And when looking at the DSP-filter rigs like IC-756Pro ff., where the user can define and arrange each of the three filters individually, the settings of 'wide' or 'narrow' become meaningless. Here a filter value of $01 corresponds to filter 1, value $02 to filter 2 and $03 to filter 3, regardless of whether filter 1 is acutally wider than filter 2 or 3.

Formerly only $01 and $02 were used for wide and narrow, medium/normal was introduced later and the data rearranged. So it can happen that 'narrow' on older rigs is programmed using $02, on other, newer rigs as $03.

Note: Please note that when omitting the filter value from this command, the results can be unexpected. I recently discovered that the IC-R8500 switches to 'wide' filter when issueing the command without filter value (for AM). On my IC-756Pro3 and the IC-R75 the filter is always set to 'Normal' when missing.