Quick jobs : H-Bridge circuit to drive a motor

To day my supervisor just pop in and throw me 8 solid-state-relay (SSR) and ADAM-4068 (Serial-I/O device) and ask me to wire a circuit to control a motor for his robot.

ADAM-6048 is a handy device that let you control digital input and output via RS-485, serial communication given a protocol in its manual. Output of ADAM is rated at 0.5 ampere so I use it to control the SSR which can operate up to 40 ampere each.

Circuit diagram is as follow, bigger line means high current cable :

Note :
RL0 NO -- Relay channel 0 of ADAM, Normally Open pin
RL0 COM -- Relay channel 0 of ADAM, Common pin

When output set to "high", current will able to flow from COM to NO. Best to imagine it as a simple switch, when push both pin will connect and let a current flowing. Then pin 1 and pin 2 of SSR will connect and let a (high) current pass through the motor.

Warning!
Unlike normal relay, SSR let current pass in only one direction, from pin 2 to pin 1 and from pin 4 to pin 3 as I indicate + and - sign in above diagram. I blown 2 SSR because of this ignorance!


SSR I'm using are Maxwell's MS-DD6040.