Garmin GTR 200, Installation Manual

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190-01553-00 GTR 200 Installation Manual
Rev. B Page B-5
NOTE
The GTR will ignore this message while transmitting on the active COM frequency.
B.2.2.2 Set Standby Frequency and Transceiver Function
This message is used to set the Standby frequency as well as the transceiver function.
Message format (GTR 200):
“GRM”.............Company identifier.
“C” ...................Message class.
“16”..................Message identifier.
mk ....................Standby frequency: m = MHz, where m = desired MHz frequency - 30h, ranging
from 118 to 136 MHz, (i.e. 76h to 88h, A2h); k = (KHz offset / 25KHz) + 30h,
ranging from 000 to 975KHz in 25 KHz steps.
a .......................Transceiver function: N = normal, M = monitor, 0 = unchanged.
“0”....................8.33 KHz offset: (ASCII) 0 = 25 KHz frequency (.000)
iiii.....................Identifier string. Note that if the identifier string is less than four characters, left
justify the string and insert spaces for empty characters. An empty identifier
string (four spaces) is allowed. Identifiers are restricted to using ASCII characters
0-9 and A-Z.
f........................Frequency type (see Extended Frequency Type Enumeration).
Example message:
$PGRMC16G>M0KOJC2<chksm><CR><LF>
This example command would set the standby frequency to 119.350 MHz with an identifier of “KOJC
ATIS”, and place the radio in Monitor mode. This is interpreted by noting that the ASCII ‘G’ corresponds
with 47h, +30h = 77h, converted to decimal equals 119 for the MHz portion. The KHz portion converts
ASCII ‘>’ to 3Eh, -30h yields Eh, x25KHz steps = 350 KHz, with no 8.33 KHz channel offset. The
identifier string portion is “KOJC” and the frequency type ‘2’ corresponds to “Automated Terminal
Information Station” in the extended frequency type enumeration.
Message format (GTR 225/GNC 255):
“GRM”.............Company identifier.
“C” ...................Message class.
“01”..................Message identifier.
mk ....................Standby frequency: m = MHz, where m = desired MHz frequency - 30h, ranging
from 118 to 136 MHz, (i.e. 76h to 88h, A2h); k = (KHz offset / 25KHz) + 30h,
ranging from 000 to 975KHz in 25 KHz steps.
a .......................Transceiver function: N = normal, M = monitor, 0 = unchanged.
“0”....................8.33 KHz offset: (ASCII) 0 = 25 KHz frequency (.000)
Example message:
$PGRMC01KFM0<chksm><CR><LF>
This example command would set the standby frequency to 123.550MHz and place the radio in Monitor
mode. This is interpreted by noting that the ASCII ‘K’ corresponds with 4Bh, +30h = 7Bh, converted to
decimal equals 123 for the MHz portion. The KHz portion converts ASCII ‘F’ to 46h, -30h yields 16h,
x25KHz steps = 550KHz , with no 8.33 KHz channel offset.