Sylk Bus; Supported Wall Modules; Sylk Bus Wiring Examples - Honeywell Centra Line MERLIN NX Series Installation Instructions Manual

MERLIN NX IP AND MST/TP VAV CONTROLLER - INSTALLATION INSTRUCTIONS
— Ground noise should not exceed the EIA-485 com-
mon mode voltage limit.
— Must conform to TIA/EIA 485 cabling guidelines.
"TIA/EIA 485 Cable Specifications" on page 19.
— Should not extend beyond a single building.
— It is recommended that you select a low baud rate
(for example, 19.2 kbps) for reliable operation
.

SYLK BUS™

Sylk™ Bus capable wall modules such as CLCMTR40x /
CLCMTR42x can be connected to the controller's Sylk™
Interface (terminals 14 and 15).
• The Sylk™ Bus is single pair, and polarity-insensitive.
• Maximum current provided at the Sylk™ Bus interface:
96 mA.
• The maximum number of wall modules depends on the
following wall module specific information:
— Sylk™ bus power consumption
— Number of parameters used
— Total config file size
The Niagara tool has an inbuilt resource calculator to
calculate the number of Sylk™ wall modules.The Sylk™
devices supported by the MERLIN NX IP and MSTP VAV
are;

Supported wall modules

CLCMTR40, CLCMTR40-H, CLCMTR40-H-CO2,
CLCMTR40-CO2, CLCMTR42, CLCMTR42-H,
CLCMTR42-H-CO2, CLCMTR42-CO2, CLCMTR71-H,
CLCMTR120 (TR75E) and CLCMTR120-H (TR75-HE)
NOTE:
The CLCMTR42x Wall Module must be version
1.00.3 or higher.
NOTE:
CLCMTR70 Wall Modules are not supported.
Table 9. Recommended max. distances from controller
to CLCMTR40x/CLCMT42x wall modules
Single twisted pair, Non-Shielded,
Stranded or Solid
18 - 22 AWG 24 AWG
(0.33 to 1mm2) (0.20 mm2)
EN1Z-1076GE51 R0722
Standard non-twisted
thermostat wire
shielded or Non-
c)
Shielded, Stranded or
Solid
18 - 24 AWG
(0.20 to 1 mm2)
Table 9. Recommended max. distances from controller
to CLCMTR40x/CLCMT42x wall modules (Continued)
See
Single twisted pair, Non-Shielded,
500 ft
(150 m)
c)
As a rule of thumb, single twisted pair (two wires per cable,
only), thicker gauge, non-shielded cable yields the best results
for longer runs.
d)
The 100 ft (30 m) distance for standard thermostat wire is
conservative but is meant to reduce the impact of any sources
of electrical noise (incl. but not limited to VFDs, electronic
ballasts, etc.). Shielded cable recommended only if there is a
need to reduce the effect of electrical noise.
These distances apply also for shielded twisted pair.

Sylk Bus Wiring Examples

14 15
IP VAV
Number of Devices: Subject to power loading - refer to device
d)
26
c)
Stranded or Solid
400 ft
(120 m)
FAN OVERRIDE
polarity
independent
IP VAV
Home Running
Daisy Chaining
documentation).
Fig. 33. Sylk™ Wiring Topologies
Standard non-twisted
thermostat wire
shielded or Non-
Shielded, Stranded or
d)
Solid
100 ft
(30 m)
Sylk Device
e.g. TR40, TR42.
to additional
Sylk devices