1.6. DeviceNetSpecification for connection

1.6. DeviceNetSpecification for connection

Figure 1.4 DeviceNet Configuration of the network

(1)    Terminating resistor

l  If a termination resistor embedded in the BD525SUBD board is to be used (DSW1 Pin1 On), do not install an additional external termination resistor.

Figure 1.5 BD525SUBD Terminating resistor

l  If a termination resistor embedded in the BD525SUBD board is not to be used (DSW Pin1 Off), install a resistor of 121 Ω (1%, 1/4 W), as shown in the following figure.

Figure 1.6 Installation of an external termination resistor

 

 

(2)    Maximum length of the trunk line of each type

Communication speed	Flat cable	Thick cable	Mid cable	Thin cable
125k bit/s	420m	500m	300m	100m
250k bit/s	200m	250m	250m	100m
500k bit/s	75m	100m	100m	100m

Table 1‑4 Length of the trunk line of the DeviceNet

(3)    Length of the drop line

Communication speed	Cumulative drop line length
125k bit/s	156m
250k bit/s	78m
500k bit/s	39m

Table 1‑5 DeviceNet Length of the drop line

(4)    Ground

l Ground the V conductor, shield, and drain lines at one locationto prevent ground loops. If possible, ground at a physical central location of the network to maximize the ground effects and minimize the effects of the external noise.

l When more than two power supplies are to be used, V+ should be cut off between the power supplies.

 

Figure 1.7 DeviceNet Installation