MODULE SET-UP
ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual
9-3
port 1-4, Narrowcast cable into port 1-1 to 1-3.
(see section 6.1)
5. From the front panel RF Test Point confirm the Narrowcast QAM RF channels are at the same level as the Broadcast
QAM RF channels. If not, correct the level difference coming into the chassis on each individual NC port.
6. Using the Hand-held Display navigate to the Tx Setup Menu.
7. Under the Tx Status menu the RF
(reference level)
reading should be approximately 0.0 dB, ± 0.5 dB. The Att (dB)
(reserve gain level)
should be between 3-4 dB (if 31 dBmV total RF power is applied to input ports).
R F
: -0.1
Att(dB): +3.5
The reserve gain is the amount of headroom below the +31 dBmV reference level.
9 .2 .2 MGC Mode (Hand-held Display)
The following provides the procedures and associated menus for configuring the DMTx4 with the Hand-held Display in the
MGC mode. When operating in the MGC mode the variable attenuator for each laser transmitter can be manually adjusted
to so the RF reference display will read 0.0 dB ± 0.5 dB.
1. Connect power to the chassis. Unit should power up (no switches).
2. Plug the RS-232 cable from the Hand-held Display into the RS-232 port on the CF-CTLR control and communications
module.
3. Using the Hand-held Display choose the appropriate slot for the desired module location.
4. Example DMT34 - With a combined Broadcast/Narrowcast total RF power of 31 dBmV plug the Broadcast cable into
port 1-4, Narrowcast cable into port 1-1 to 1-3.
(see section 8.1)
5. From the front panel RF Test Point confirm the Narrowcast QAM RF channels are at the same level as the Broadcast
QAM RF channels. If not, correct the level difference coming into the chassis on each individual NC port.
6. Using the Hand-held Display navigate to the Setup/Mode Settings menu.
S
etup Menu
Tx Status Menu
M
ode Setting Menu
Gain Setting Menu
7. Under the Setup/Mode Settings menu place the unit in MGC mode and save the setting.
M
ode: MGC
Save: No ( AGC)
S
ave: Yes (MGC)
Prev Menu
8. Next using the Hand-held Display navigate to the Setup/Gain Settings menu.
G
ain Setting Menu
OPTOut Setting Menu
9. Select the internal laser transmitter to be adjusted (Sel_Ch)
10. Under the Gain Setting Menu note the
RF Lvl
.
Rf Lvl (rdB): -1.0
Gain(steps): 4.5
11. Using the
Gain (Steps)
menu add or remove the attenuation steps until the
RF Lvl
displays 0.0 dB - ± 0.5 dB in the
Tx Status/RF menu.
Rf Lvl (rdB): -0.1
Gain(steps): -3.5
12. Save Gain (Steps) value.
Gain(steps): -3.5
S
ave: Yes (-3.5)
13. Next using the Hand-held Display navigate to the Tx Status menu.
T x
Status Menu
Alarm Menu
14. Under the Tx Status Menu note the
RF
level. The level should be the same value as the
RF Lvl
value set in step #10.
The Att (dB) value should be +3.5 ± 0.5 dB with a total combined input power of 31 dBmV at the back of the chassis.
CHAPTER 9:
