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DC4 - BMS Slave Unit
  
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© 2004 by CapeSoft Electronics (Pty) Ltd
www.capesoft.com
     

The DC4 is a very cost effective extension of the Siemens Building Technologies System 600 BMS. It acts as a remote extension of the MBC or RBC. The system 600 programmer has access to the 28 points on the DC4. Each point can be unbundled and used in the usual manner including trending etc.

All connections to the DC4 are by means of plug-in screw terminal connectors which provides for quick, convenient installation, commissioning and maintenance.

Features
  8 Digital outputs  
8 Digital inputs
8 Analog inputs
4 Analog outputs
BMS communications support (Siemens Building Technologies System 600 compatible)
Accepts 10k, 47k and 100k NTC thermistor temperature sensors
Analog inputs can be individually selected as 0-10 Volt or NTC sensor
     


Technical Data

  Operating voltage 24 VAC, 2 VA  
Temperature sensors
Sensing elements - NTC thermistors 10k, 47k or 100k
Temperature range -10 to 50º C, 0.25º C Resolution
0-10 Volt analog input 0 to 10 Volt, 0.04 Volt Resolution
0-10 Volt analog output 0 to 10 Volt, 0.0476 Volt Resolution
Source - sink current 1 mA max
Digital outputs 220 VAC, 1 Amp running - 4 Amp max
Digital inputs 24 VAC, 20 mA current
     


Controller Setup
The controllers must each be programmed with an address for BMS operation. The address is set by means of the dip switch on the controller. The dip switch settings have the following values. 

Controller Setup
  Switch Number OFF Value ON Value  
1 0 1
2 0 2
3 0 4
4 0 8
5 0 16
     
 
DC4 Dip Switch The address is calculated by adding the values together.

The dip switch shown here has switches 1 & 2 OFF while 3,4 & 5 are ON. The address is calculated as 4 + 8 + 16 = 28
The analog inputs can be individually configured. Each input can be selected as either 0-10 Volt, or a NTC thermistor sensor input. There are 2 jumper settings for each input.
DC4 Jumper The first jumper selects either 0-10 Volt or NTC thermistor input.
DC4 Jumper The second jumper selects either 0-10 Volts or which value of NTC thermistor is attached.


DC4 Connections

DC4 Connections



DC4 Points List (BMS) Version A-F - Application 150
  Pnt Description Units On / Off Slope Intercept Type  
1 DI 1   ON.OFF 1 0 LDI
2 DI 2   ON.OFF 1 0 LDI
3 DI 3   ON.OFF 1 0 LDI
4 DI 4   ON.OFF 1 0 LDI
5 DI 5   ON.OFF 1 0 LDI
6 DI 6   ON.OFF 1 0 LDI
7 DI 7   ON.OFF 1 0 LDI
8 DI 8   ON.OFF 1 0 LDI
9 DO 1   ON.OFF 1 0 LDO
10 DO 2   ON.OFF 1 0 LDO
11 DO 3   ON.OFF 1 0 LDO
12 DO 4   ON.OFF 1 0 LDO
13 DO 5   ON.OFF 1 0 LDO
14 DO 6   ON.OFF 1 0 LDO
15 DO 7   ON.OFF 1 0 LDO
16 DO 8   ON.OFF 1 0 LDO
17 TEMP 1 DEG C   0.25 -10 LAI
18 TEMP 2 DEG C   0.25 -10 LAI
19 TEMP 3 DEG C   0.25 -10 LAI
20 TEMP 4 DEG C   0.25 -10 LAI
21 TEMP 5 DEG C   0.25 -10 LAI
22 TEMP 6 DEG C   0.25 -10 LAI
23 TEMP 7 DEG C   0.25 -10 LAI
24 TEMP 8 DEG C   0.25 -10 LAI
25 0-10V IN 1 VOLTS   0.04 0 LAI
26 0-10V IN 2 VOLTS   0.04 0 LAI
27 0-10V IN 3 VOLTS   0.04 0 LAI
28 0-10V IN 4 VOLTS   0.04 0 LAI
29 0-10V IN 5 VOLTS   0.04 0 LAI
30 0-10V IN 6 VOLTS   0.04 0 LAI
31 0-10V IN 7 VOLTS   0.04 0 LAI
32 0-10V IN 8 VOLTS   0.04 0 LAI
33 0-10V OUT 1 VOLTS   0.0476 0 LAO
34 0-10V OUT 2 VOLTS   0.0476 0 LAO
35 0-10V OUT 3 VOLTS   0.0476 0 LAO
36 0-10V OUT 4 VOLTS   0.0476 0 LAO
     


DC4 Points List (BMS) Version G-I - Application 151
  Pnt Description Units On / Off Slope Intercept Type  
1 DI 1   ON.OFF 1 0 LDI
2 DI 2   ON.OFF 1 0 LDI
3 DI 3   ON.OFF 1 0 LDI
4 DI 4   ON.OFF 1 0 LDI
5 DI 5   ON.OFF 1 0 LDI
6 DI 6   ON.OFF 1 0 LDI
7 DI 7   ON.OFF 1 0 LDI
8 DI 8   ON.OFF 1 0 LDI
9 DO 1   ON.OFF 1 0 LDO
10 DO 2   ON.OFF 1 0 LDO
11 DO 3   ON.OFF 1 0 LDO
12 DO 4   ON.OFF 1 0 LDO
13 DO 5   ON.OFF 1 0 LDO
14 DO 6   ON.OFF 1 0 LDO
15 DO 7   ON.OFF 1 0 LDO
16 DO 8   ON.OFF 1 0 LDO
17 TEMP 1 DEG C   0.25 -10 LAI
18 TEMP 2 DEG C   0.25 -10 LAI
19 TEMP 3 DEG C   0.25 -10 LAI
20 TEMP 4 DEG C   0.25 -10 LAI
21 TEMP 5 DEG C   0.25 -10 LAI
22 TEMP 6 DEG C   0.25 -10 LAI
23 TEMP 7 DEG C   0.25 -10 LAI
24 TEMP 8 DEG C   0.25 -10 LAI
25 0-10V IN 1 VOLTS   0.04 0 LAI
26 0-10V IN 2 VOLTS   0.04 0 LAI
27 0-10V IN 3 VOLTS   0.04 0 LAI
28 0-10V IN 4 VOLTS   0.04 0 LAI
29 0-10V IN 5 VOLTS   0.04 0 LAI
30 0-10V IN 6 VOLTS   0.04 0 LAI
31 0-10V IN 7 VOLTS   0.04 0 LAI
32 0-10V IN 8 VOLTS   0.04 0 LAI
33 0-10V OUT 1 VOLTS   0.05 0 LAO
34 0-10V OUT 2 VOLTS   0.05 0 LAO
35 0-10V OUT 3 VOLTS   0.05 0 LAO
36 0-10V OUT 4 VOLTS   0.05 0 LAO
     


DC4 Points List (BMS) Version J onwards - Application 152
  Pnt Description Units On / Off Slope Intercept Type  
1 DI 1   ON.OFF 1 0 LDI
2 DI 2   ON.OFF 1 0 LDI
3 DI 3   ON.OFF 1 0 LDI
4 DI 4   ON.OFF 1 0 LDI
5 DI 5   ON.OFF 1 0 LDI
6 DI 6   ON.OFF 1 0 LDI
7 DI 7   ON.OFF 1 0 LDI
8 DI 8   ON.OFF 1 0 LDI
9 DO 1   ON.OFF 1 0 LDO
10 DO 2   ON.OFF 1 0 LDO
11 DO 3   ON.OFF 1 0 LDO
12 DO 4   ON.OFF 1 0 LDO
13 DO 5   ON.OFF 1 0 LDO
14 DO 6   ON.OFF 1 0 LDO
15 DO 7   ON.OFF 1 0 LDO
16 DO 8   ON.OFF 1 0 LDO
17 TEMP 1 DEG C   0.25 -10 LAI
18 TEMP 2 DEG C   0.25 -10 LAI
19 TEMP 3 DEG C   0.25 -10 LAI
20 TEMP 4 DEG C   0.25 -10 LAI
21 TEMP 5 DEG C   0.25 -10 LAI
22 TEMP 6 DEG C   0.25 -10 LAI
23 TEMP 7 DEG C   0.25 -10 LAI
24 TEMP 8 DEG C   0.25 -10 LAI
25 0-10V IN 1 VOLTS   0.04 0 LAI
26 0-10V IN 2 VOLTS   0.04 0 LAI
27 0-10V IN 3 VOLTS   0.04 0 LAI
28 0-10V IN 4 VOLTS   0.04 0 LAI
29 DAY.NGT   NIGHT.DAY 1 0 LDO
30 0-10V IN 5 VOLTS   0.04 0 LAI
31 0-10V IN 6 VOLTS   0.04 0 LAI
32 0-10V IN 7 VOLTS   0.04 0 LAI
33 0-10V IN 8 VOLTS   0.04 0 LAI
34 0-10V OUT 1 VOLTS   0.05 0 LAO
35 0-10V OUT 2 VOLTS   0.05 0 LAO
36 0-10V OUT 3 VOLTS   0.05 0 LAO
37 0-10V OUT 4 VOLTS   0.05 0 LAO
     


Dimensions


DC4 Dimensions

Special Notes

There are a few items to bear in mind when using the DC4.

Note 1
The standard DC4 only supports SI units. Non SI can be supplied on request.

Note 2
The points numbered 17 to 24 and those numbered 25 to 32 are both representations of the same physical analog inputs. When the analog input is connected to a NTC thermistor temperature sensor, then unbundle the point from the points 17 to 24. When using the analog input as 0 to 10 Volts then unbundle the point from the points 25 to 32. The points 17 to 24 are corrected, by the DC4, to allow for the non-linearity of the thermistor curve.

Example:
 If analog input 1 is connected to a 100k NTC thermistor then you would unbundle the point as address TCCLDD17 with a slope of 0.25, an intercept of -10 and the type L.

Example:
If the analog input 2 is connected to a 0 to 10 Volt device then you would unbundle the point as address TCCLDD26 with a slope of 0.04, an intercept of 0 and the type L. This would return the value 0 to 10. If the 0 to 10 Volt device is, for instance, a pressure sensor with the range 0 to 500 Pa, you might prefer to unbundle the point as address TCCLDD26 with a slope of 2.0, an intercept of 0 and the type L. This would return the values 0 to 500.

The slope to use is calculated as follows:
SLOPE = 0.004 X RANGE

The range was 500 so the slope became:
SLOPE = 0.004 X 500 = 2.0

Note 3
The Siemens Building Technologies 10k NTC sensor has an internal diode which offsets the value read by the DC4. These sensors can be used. The intercept must be changed from -10 to -5 to correct for effect of the internal diode. The BMS standard report will however show a value which is 5 Deg C lower that actual. The unbundled point will show the correct value.

Note 4
The DC4 is fabricated without any non-volatile (permanent) memory. Due to this design any "OPERATOR" priority commands will be lost during a power failure.

Example:
So for instance if you were to unbundle a digital output as FANRUN. Then if you commanded FANRUN to ON, your point FANRUN would appear in the point log as:

FANRUN ( ) ON -N- P:OPER

Should the power to the DC4 become interrupted or the communication to the DC4 be lost for more than 30 seconds, then when the DC4 returns from failure, the point log would show the following:

FANRUN ( ) OFF -N- P:OPER

The FANRUN would default to OFF and remain as such until it is changed by another operator command or be released from OPERATOR priority and change under program control.

The points can be commanded using POINT COMMAND LCTLR SET etc. These commands will be restored by the BMS when the DC4 returns from failure.

CapeSoft Contact Details
  Email:  
Telephone: +27 21 715 4000
Fax: +27 21 715 2535
Post: PO Box 511, Plumstead, 7801, South Africa