Scheduled Maintenance

The S-LX system is designed to be free of scheduled maintenance for its entire service life. No scheduled maintenance regime is required.

Reactive Maintenance

In the rare event of system failure, reactive maintenance may be required to restore the S-LX system to full operation. In the event of system malfunction:

Use the troubleshooting guide below to identify the likely cause.
Refer to the relevant restorative maintenance instruction found later in this guide
If unsuccessful, please contact MPEC Technology Ltd for further support.
- Telephone: 01332 363 979. Available Monday to Friday 8 AM to 4 PM UK time.
- Email: support@mpec.co.uk. Response typically within 24 hours.

Troubleshooting

Symptoms of identified failure modes are listed below. The “probable cause” field lists fault conditions in order of likelihood and should be eliminated in order. The “Remedial Action” column links to fault finding and maintenance task instructions.

Symptom	Probable Causes	Remedial Action

Symptom	Probable Causes	Remedial Action
Total Loss of All Function	AC Power Wiring Fault	Test and Replace AC Power Wiring
Total Loss of All Function	HZS AC PSU Fault	Replace HZS Module
Total Loss of S-LX compute module	DC Power Wiring Fault	Test and Replace DC Power Wiring
	HZS DC PSU Fault	Replace HZS Module
	S-LX module hardware Failure	Replace S-LX Compute Module
Intermittent or Total Loss of Serial Communications	RS232 Wiring fault	Test and Correct RS232 Wiring
	RS485 Wiring fault	Test and Correct RS485 Wiring
	HZS Hardware Failure	Replace HZS module
	S-LX hardware Failure	Replace S-LX compute module
	Electromagnetic Interference	Screen RS232 Cable
	Electromagnetic Interference	Check and Correct Earth Bonding
Intermittent or Total Loss of Ethernet Communications	Ethernet wiring Fault	Test and Correct Ethernet Wiring
	S-LX hardware Failure	Replace S-LX compute module
	Electromagnetic Interference	Screen Ethernet Cable
	Electromagnetic Interference	Check and Correct Earth Bonding
Intermittent or Total Loss of wireless communication	SIM fault	Check Service Provision of SIM
	SIM Fault	Replace SIM
	Sub-optimal antenna placement	Re-site Antenna
	Antenna or Antenna cable damage	Replace Antenna
	Wireless Modem hardware failure	Replace S-LX compute module
	SIM card reader Fault	Replace S-LX compute module
Intermittent or Total Loss of Monitored Signal Function	RS232 wiring fault	Test and Correct RS232 Wiring
	HZS Hardware Failure	Replace HZS module
	Electromagnetic Interference	Screen RS232 Cable
S-LX or HZS modules not secured to DIN rail	Loose device fastenings	Check Physical Fitment
	Failed device fastening	Replace S-LX compute module
	Failed device fastening	Replace HZS module
Physical damage to modules	Impact damage	Replace S-LX compute module
Physical damage to modules	Impact damage	Replace HZS module
Suspected Earth Fault	Earth cable fitted	Remove Earth Cable
	AC Wiring Fault	Test and Replace AC Power Wiring
	DC Wiring Fault	Test and Replace DC Power Wiring
	RS232 Wiring Fault	Test and Correct RS232 Wiring
	RS485 Wiring Fault	Test and Correct RS485 Wiring
	Ethernet Wiring Fault	Test and Correct Ethernet Wiring
	HZS module Fault	Replace HZS module
	S-LX compute module fault	Replace S-LX compute module
Intermittent or Total Failure of SD card	SD card fault	Replace SD card
USB Port Malfunction	Inoperable or physically damaged	Replace S-LX compute module
USB Eject button malfunction	Inoperable or physically damaged	Replace S-LX compute module

Reactive Maintenance Instructions

Test and Replace AC Power Wiring

Test	Outcome	Action

Test	Outcome	Action
Test for voltage either side of the primary fuse	No voltage below fuse indicates blown fuse	Replace fuse
Test for voltage at AC input plug	No voltage implies a wiring fault	De-energise power circuit and check cables for continuity and physical integrity of all connections.
Test for voltage at AC input plug	Voltage implies HZS device fault	Check mating of power connector and soundness of ferrule crimps. If no fault found, replace HZS device

Replace HZS Module

De-energise the incoming power supply and test that AC voltage is not present at the HZS power input terminals
Unscrew and remove all device plugs.
The HZS is retained by a sprung steel clip, which will easy pop-off the DIN rail, however loosening any end stops may aid removal.
Replace with a new HZS device by clipping it to the DIN rail.
Tighten any end-stops that may have been loosened.
Reinsert all plugs. Plugs are colour coded and feature cable beads to aid with replacement, but take care to ensure all plugs are reinstalled in their original positions.
Repeat the commissioning steps found in the installation guide.

Test and Replace DC Power Wiring

Test	Outcome	Action

Test	Outcome	Action
Test for voltage at DC output of HZS device	No voltage indicates failed HZS	Check mating of power connector and soundness of ferrule crimps. If no fault found, replace HZS device
Test for voltage at the DC input of the S-LX device	No voltage implies a wiring fault	De-energise power circuit and check cables for continuity and physical integrity of all connections.
Test for voltage at the DC input of the S-LX device	Voltage implies S-LX device fault	Check mating of power connector and soundness of ferrule crimps. If no fault found, replace S-LX device

Replace S-LX Compute Module

The HZS device does not need to be powered down to replace the S-LX device.
Unscrew and remove all device plugs.
The S-LX is retained using two sliding plastic clips at the rear of the device. Withdrawing either top or bottom clip will allow removal of the device from the DIN rail. loosening any end stops may aid removal.
Replace with a new S-LX device by clipping it to the DIN rail.
Your replacement device will have been pre-configured by MPEC to be a direct replacement.
Tighten any end-stops that may have been loosened.
Reinsert all plugs. Plugs are colour coded and feature cable beads to aid with replacement, but take care to ensure all plugs are reinstalled in their original positions, particularly the Ethernet connections
Repeat the commissioning steps found in the installation guide.

Test and Correct RS232 Wiring

Disturbing RS232 wiring in some applications may disrupt the operation of signalling equipment

Check RS232 wiring follows the core assignments that shown in the overlay diagram.
Pay particular attention to pin assignments and soundness of solder connection in DB-9 plugs
Pay particular attention to the soundness of connection made on “punch-down” blocks
Check for secure mating of all plug coupler connections
Check for secure crimping and fastening of terminal blocks.
Test replacement of any pre-moulded “splitter” cables.

Test and Correct RS485 Wiring

Check RS485 wiring follows the core assignments that shown in the overlay diagram.
Check for correct connection of TX and RX RS485 pairs between S-LX and HZS. They are easily swapped.
Check for secure mating of all plug coupler connections
Check for secure crimping and fastening of terminal blocks.
Test replacement of any pre-moulded “splitter” cables.

Screen RS232 Cable

Supplied RS232 cable is screened, however the screen is not connected to a functional earth point.
A functional earth point may be found on the shell of the DB-9 connector of monitored equipment
- In this instance, it is possible to connect the cable screen the the plug back-shell.
- Contact MPEC is supply of a screened cable is required.

Check and Correct Earth Bonding

Good functional earth bonding can guard against electromagnetic interference.
A functional bond is made by the HZS mounting clip. Where practical, check that a good electrical connection exists between the clip and equipment racking, and that equipment racking is properly earthed.
Functional bonding can also be made by connecting the E terminal of the HZS power connector to a suitable earthing point, using the shortest wiring run possible.

Test and Correct Ethernet Wiring

The simplest way to test Ethernet wiring is to swap out the cable, and then testing both old and new cable to check for faults.
If a known good cable does not correct the issue, check device IP settings..

Screen Ethernet Cable

The unscreened cable must be replaced with a screened cable.
As the S-LX system is isolated from earth, the Ethernet shell on the S-LX device is not connected to a functional earth
The functional earth connection must be made out the non-S-LX end of the cable.

Check Service Provision of SIM

The SIM serial number can be located on the side of the S-LX device
Contact the SIM provider (O2) and check that the SIM is active, and has public Internet access available.

Replace SIM

The SIM resides behind the card-cover found next to the antenna connector.
The cover slides off and held in place with small screw.

Re-site Antenna

Antenna placement has a large bearing on system performance
Even small movements can make a significant difference.
Commercially available signal strength meters, and even personal phones may be used gauge appropriate places to site the antenna.
The S-LX module gives an indication of received signal strength. The indicator only updates once per minute, so patience is required when assessing the impact of any movement

Replace Antenna

Damaged antennas may need like-for-like replacement. Simply unscrew the GSM antenna cable and replace the antenna.
In areas of very poor signal strength, higher-gain antennas may be required. Contact MPEC to discuss.

Check Physical Fitment

Check S-LX retaining clips are securely fastened.
Check HZS device clip is fully locked onto the DIN rail.
Check that end stops are firmly butted against the devices and secure.

Remove Earth Connection

If an earth fault is suspected to be caused by the S-LX system, removal of the earth bonding may reveal the root cause, should the fault disappear.

Replace SD Card

The SD card resides behind the card-cover found next to the antenna connector.
The cover slides off and held in place with small screw.

SA380 Series Documentation

Trouble Shooting & Maintenance