H-Link Ii Specifications; Hardware Characteristics; H-Link Ii System - Hitachi PC-ARF Technical Catalogue

2 Control solutions

H-LINK II Specifications

2.3 H-LINK II Specifications

2.3.1 Hardware characteristics

Elements
Communication cable
Communication system
Communication method
Transmission speed
Cable length Maximum
Either package units or water chillers only can be connected in an H-LINK communication line. Mixed connection of pack-
age units and water chillers is not permitted.

2.3.2 H-LINK II System

H-LINK II improves the characteristics of H-LINK I. The following table compares both systems and is valid for only 1000
meters of H-LINK line:
Connectable outdoor units
Connectable indoor units
Units (outdoor and indoor)
Maximum connectable devices
H-LINK II has a limit of 200 connected devices and a maximum number of 160 indoor units. The following limitation must
always be respected:
Therefore, in a case of 64 outdoor units connected to the same H-LINK, only 136 other elements may be connected (includ-
ing indoor units and control systems).
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Restrictions when using PSC-5HR accessory
H-LINK line length could be up to 1000 meters. It can be increased up to 5000 meters using up to 4 PSC-5HR devices.
Each of them adds 1000 meters to the line, affecting the quantity of indoor units that can be connected to the same H-LINK.
Each H-LINK line repeater (PSC-5HR) counts as 16 indoor units. The following table summarizes the relation between the
quantity of PSC-5HR devices and the maximum number of indoor and outdoor units allowed in each case.
Number of PSC-5HR
0
1
2
3
4
25 25
TCGB0106 rev.0 - 12/2014
Outdoor units + Indoor units + other H-LINK devices ≤ 200
Number of Maximum number of indoor
outdoor units units and control systems
1
20
40
50
60
64
Maximum length of H-LINK
1000 meters
2000 meters
3000 meters
4000 meters
5000 meters
Specifications
Twin wire, without polarity
Half-duplex
Asynchronous
9600 Bauds
1000 m (5000 m if applied four PSC-5HR devices)
H-LINK I H-LINK II
16 64
128 160
- 176
145 200
64
160
160
150
140
136
Maximum number of indoor and outdoor units
176
160
144
128
112
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